Interstage HTTP Server: Two Security Vulnerabilities (CVE-2011-3368/ CVE-2011-0419). February 20th, 2012

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1. Description

1. The following vulnerability has been confirmed when the host uses the Interstage HTTP Server reverse proxy feature: Remote access to an optional host may be allowed.
   This vulnerability corresponds to CVE-2011-3368.
   
   However, unless the following conditions apply, Interstage HTTP Server is not affected by this vulnerability:
   
   1. The reverse proxy feature is initiated by the "[P]" flag of the RewriteRule directive in the configuration file (httpd.conf), and
   2. $N (N: a numeric value between 1 and 9) is specified just after the connection destination host name (Example: images.example.com) used by the reverse proxy feature.
      
      Example: RewriteRule (.*)\.(jpg|gif|png) http://images.example.com$1.$2 [P]
2. A Denial of Service (DoS) vulnerability has been confirmed in the Interstage HTTP Server directory list automatic generation feature.
   This vulnerability corresponds to CVE-2011-0419.
   
   However, unless the following conditions apply, Interstage HTTP Server is not affected by this vulnerability:
   
   1. "Indexes" is set for the Options directive in the configuration file (httpd.conf), and
   2. "IgnoreClient" is not set for the IndexOptions directive in the configuration file (httpd.conf), and
   3. In the content posted on Interstage HTTP Server, there are files with long file names (approximately 50 bytes or greater).

Fujitsu provides security patches shown in 3.
Please apply them as soon as possible.

2. Impact

1. Illegal host access may occur because of a modified request that was sent by a remote attacker.
2. A modified request sent by a remote attacker may consume large amounts of CPU time on the Web server and cause Denial of Service (DoS).

3. Affected systems and corresponding action

3-1. Affected systems:

GP7000F, PRIMEPOWER, PRIMERGY, GP5000, CELSIUS, AT-compatible machine, PRIMEQUEST, SPARC Enterprise

3-2. Affected products and required patch

[*a] Affected by CVE-2011-3368: For details, refer to a) of "3-3. Workaround" below.
[*b] Affected by CVE-2011-0419: For details, refer to b) of "3-3. Workaround" below.

Note: Determining the affected product

To check the software version, refer to the "FUJITSU SOFTWARE RELEASE GUIDE" supplied with the product.

3-3. Workaround

1. Set "/" just before the URL pattern of the RewriteRule directive and just after the destination host name (e.g. images.example.com) of the configuration file (httpd.conf).
   After the file is edited, save the file and restart the Interstage HTTP Server.
   
   [Before edit]
      Example: RewriteRule (.*)\.(jpg|gif|png) http://images.example.com$1.$2 [P]
   
   [After edit]
      Example: RewriteRule /(.*)\.(jpg|gif|png) http://images.example.com/$1.$2 [P]
2. Prevent the problem in one of the following ways.
   
   1. If "Indexes" is set for the Options directive in the configuration file (httpd.conf), disable the directory list automatic generation feature by deleting "Indexes".
      After the file is edited, save the file and restart the Interstage HTTP Server.
   2. Disable the request queries by setting "IgnoreClient" for the IndexOptions directive in the configuration file (httpd.conf).
      After the file is edited, save the file and restart the Interstage HTTP Server.
   3. If there are files with long file names in the content posted on Interstage HTTP Server, change the file name to a shorter name (approximately less than 50 bytes).

4. Related information

1. CVE-2011-3368
   The mod_proxy module in the Apache HTTP Server 1.3.x through 1.3.42, 2.0.x through 2.0.64, and 2.2.x through 2.2.21 does not properly interact with use of (1) RewriteRule and (2) ProxyPassMatch pattern matches for configuration of a reverse proxy, which allows remote attackers to send requests to intranet servers via a malformed URI containing an initial @ (at sign) character.
   http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-3368
2. CVE-2011-0419
   Stack consumption vulnerability in the fnmatch implementation in apr_fnmatch.c in the Apache Portable Runtime (APR) library before 1.4.3 and the Apache HTTP Server before 2.2.18, and in fnmatch.c in libc in NetBSD 5.1, OpenBSD 4.8, FreeBSD, Apple Mac OS X 10.6, Oracle Solaris 10, and Android, allows context-dependent attackers to cause a denial of service (CPU and memory consumption) via *? sequences in the first argument, as demonstrated by attacks against mod_autoindex in httpd.
   http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-0419

5. Revision history

• February 20th, 2012: 2nd release
  
  • Change the Patch ID in "3-2. Affected products and required patch".
  • Add some products to "3-2. Affected products and required patch".
• October 31st, 2011: Initial release