Apache vulnerability 'Apache HTTP Server mod_rewrite' from scan
2 years ago
Originally Published: 2007-04-05
Article Number
000059620
Applies To
RSA Certificate Manager
RSA Registration Manager
Keon Certificate Authority
Apache Webserver
Issue
Apache vulnerability "Apache HTTP Server mod_rewrite" from scan
ISOC detected high vulnerabilities "Apache HTTP Server mod_rewrite Vulnerability" on the web servers.

The Apache HTTP Server mod rewrite vulnerability exists in Apache that may allow for code execution or a denial of service.

Apache is a popular, open source web server application.  A vulnerability is present in Apache that may allow remote code execution or a denial of service attack. The flaws reside in the mod_rewrite module through:

1) allowing control of a portion of a rewritten URL, and
2) no flag control is available such as Forbidden, Gone or NoEscape.

The default installation of Apache is not vulnerable as it does not include use of this rewrite module. Recommendation:

The vendor has made updates available for remediation here:
<http://httpd.apache.org/>  Sun Microsystems has released patches for affected Solaris 8, 9, and 10 systems. Please refer to the vendor's advisories for more information:
<http://sunsolve.sun.com/search/document.do?assetkey=1-26-102662-1>
<http://sunsolve.sun.com/search/document.do?assetkey=1-26-102663-1>
Cause
 RSA Certificate Manager (RCM) and RSA Registration Manager (RRM) web servers are compiled with mod_rewrite module. 

Resolution
On Windows, running the following command from the WebServer\bin directory lists the modules that are compiled with Apache:

 apache -l

But the rewrite engine is turned on only for SCEP server. The rule RCM uses is listed below, and as per this rule, the URL http://myserver:446/<jur_id>/pkiclient.exe gets converted to http://myserver:446/pkiclient.exe?id=<jur_id>:

 RewriteRule ^/([^/]*)/pkiclient.exe /pkiclient.exe?id=$1 [QSA]

Based on this, RCM and RRM are not susceptible.