Apache Tomcat XSS vulnerability in Accept-Language header processing

Tuesday, 19 June 2007

CVE-2007-1358: Apache Tomcat XSS vulnerability in Accept-Language
header processing

Severity:
Low (cross-site scripting)

Vendor:
The Apache Software Foundation

Versions Affected:
Tomcat 4.0.0 to 4.0.6
Tomcat 4.1.0 to 4.1.34
Tomcat 5.0.0 to 5.0.30
Tomcat 5.5.0 to 5.5.20
Tomcat 6.0.0 to 6.0.5

Description:
Web pages that display the Accept-Language header value sent by the
client are susceptible to a cross-site scripting attack if they assume
the Accept-Language header value conforms to RFC 2616. Under normal
circumstances this would not be possible to exploit, however older
versions of Flash player were known to allow carefully crafted
malicious Flash files to make requests with such custom headers.
Tomcat now ignores invalid values for Accept-Language headers that do
not conform to RFC 2616.

Mitigation:
1. Upgrade to fixed version
2. Escape values obtained from Accept-Language header before use.

Credit:
This issue was reported by Masato Anzai and Toshiharu Sugiyama.

References:
http://tomcat.apache.org/security.html