The balancer_handler function in mod_proxy_balancer in the Apache HTTP Server 2.2.0 through 2.2.6, when a threaded Multi-Processing Module is used, allows remote authenticated users to cause a denial of service (child process crash) via an invalid bb variable.

The remote Oracle Linux 5 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2008-0008 advisory.

    [2.2.3-12.el5_1.3.0.1]
     - use oracle index page oracle_index.html, update vstring and distro

     [2.2.3-12.el5_1.3]
     - further update to backport for CVE-2007-6421 (#427240)

     [2.2.3-12.el5_1.2]
     - updated backport for CVE-2007-6421 (#427240)

     [2.2.3-11.el5_1.1]
     - add security fixes for CVE-2007-6388, CVE-2007-6421        and CVE-2007-6422 (#427240)
     - add security fix for CVE-2007-4465, CVE-2007-5000 (#421631)
     - add security fix for mod_proxy_ftp UTF-7 XSS (#427745)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

A flaw was found in the mod_proxy module. On sites where a reverse proxy is configured, a remote attacker could send a carefully crafted request that would cause the Apache child process handling that request to crash. On sites where a forward proxy is configured, an attacker could cause a similar crash if a user could be persuaded to visit a malicious site using the proxy. This could lead to a denial of service if using a threaded Multi-Processing Module. (CVE-2007-3847)

A flaw was found in the mod_autoindex module. On sites where directory listings are used, and the 'AddDefaultCharset' directive has been removed from the configuration, a cross-site scripting attack might have been possible against Web browsers which do not correctly derive the response character set following the rules in RFC 2616.
(CVE-2007-4465)

A flaw was found in the mod_imagemap module. On sites where mod_imagemap was enabled and an imagemap file was publicly available, a cross-site scripting attack was possible. (CVE-2007-5000)

A flaw was found in the mod_status module. On sites where mod_status was enabled and the status pages were publicly available, a cross-site scripting attack was possible. (CVE-2007-6388)

A flaw was found in the mod_proxy_balancer module. On sites where mod_proxy_balancer was enabled, a cross-site scripting attack against an authorized user was possible. (CVE-2007-6421)

A flaw was found in the mod_proxy_balancer module. On sites where mod_proxy_balancer was enabled, an authorized user could send a carefully crafted request that would cause the Apache child process handling that request to crash. This could lead to a denial of service if using a threaded Multi-Processing Module. (CVE-2007-6422)

A flaw was found in the mod_proxy_ftp module. On sites where mod_proxy_ftp was enabled and a forward proxy was configured, a cross-site scripting attack was possible against Web browsers which do not correctly derive the response character set following the rules in RFC 2616. (CVE-2008-0005)

Updated Apache httpd packages that fix several security issues are now available for Red Hat Enterprise Linux 5.

This update has been rated as having moderate security impact by the Red Hat Security Response Team.

The Apache HTTP Server is a popular Web server.

A flaw was found in the mod_imagemap module. On sites where mod_imagemap was enabled and an imagemap file was publicly available, a cross-site scripting attack was possible. (CVE-2007-5000)

A flaw was found in the mod_autoindex module. On sites where directory listings are used, and the 'AddDefaultCharset' directive has been removed from the configuration, a cross-site scripting attack might have been possible against Web browsers which do not correctly derive the response character set following the rules in RFC 2616.
(CVE-2007-4465)

A flaw was found in the mod_status module. On sites where mod_status was enabled and the status pages were publicly available, a cross-site scripting attack was possible. (CVE-2007-6388)

A flaw was found in the mod_proxy_balancer module. On sites where mod_proxy_balancer was enabled, a cross-site scripting attack against an authorized user was possible. (CVE-2007-6421)

A flaw was found in the mod_proxy_balancer module. On sites where mod_proxy_balancer was enabled, an authorized user could send a carefully crafted request that would cause the Apache child process handling that request to crash. This could lead to a denial of service if using a threaded Multi-Processing Module. (CVE-2007-6422)

A flaw was found in the mod_proxy_ftp module. On sites where mod_proxy_ftp was enabled and a forward proxy was configured, a cross-site scripting attack was possible against Web browsers which do not correctly derive the response character set following the rules in RFC 2616. (CVE-2008-0005)

Users of Apache httpd should upgrade to these updated packages, which contain backported patches to resolve these issues. Users should restart httpd after installing this update.

A number of vulnerabilities were found and fixed in the Apache 2.2.x packages :

A flaw found in the mod_imagemap module could lead to a cross-site scripting attack on sites where mod_imagemap was enabled and an imagemap file was publically available (CVE-2007-5000).

A flaw found in the mod_status module could lead to a cross-site scripting attack on sites where mod_status was enabled and the status pages were publically available (CVE-2007-6388).

A flaw found in the mod_proxy_balancer module could lead to a cross-site scripting attack against an authorized user on sites where mod_proxy_balancer was enabled (CVE-2007-6421).

Another flaw in the mod_proxy_balancer module was found where, on sites with the module enabled, an authorized user could send a carefully crafted request that would cause the apache child process handling the request to crash, which could lead to a denial of service if using a threaded MPM (CVE-2007-6422).

A flaw found in the mod_proxy_ftp module could lead to a cross-site scripting attack against web browsers which do not correctly derive the response character set following the rules in RFC 2616, on sites where the mod_proxy_ftp module was enabled (CVE-2008-0005).

The updated packages have been patched to correct these issues.

This update fixes multiple bugs in apache :

  - cross-site scripting problem in mod_imap.
    (CVE-2007-5000)

  - cross-site scripting problem in mod_status.
    (CVE-2007-6388)

  - cross-site scripting problem in the ftp proxy module.
    (CVE-2008-0005)

  - cross-site scripting problem in the error page for     status code 413. (CVE-2007-6203)

  - cross-site scripting problem in mod_proxy_balancer.
    (CVE-2007-6421)

  - A flaw in mod_proxy_balancer allowed attackers to crash     apache. (CVE-2007-6422)

This update fixes multiple bugs in apache :

  - cross site scripting problem in mod_imap (CVE-2007-5000)

  - cross site scripting problem in mod_status     (CVE-2007-6388)

  - cross site scripting problem in the error page for     status code 413 (CVE-2007-6203)

  - cross site scripting problem in mod_proxy_balancer     (CVE-2007-6421)

  - A flaw in mod_proxy_balancer allowed attackers to crash     apache (CVE-2007-6422)

This update fixes multiple bugs in apache :

  - cross site scripting problem in mod_imap (CVE-2007-5000)

  - cross site scripting problem in mod_status     (CVE-2007-6388)

  - cross site scripting problem in the ftp proxy module     (CVE-2008-0005)

  - cross site scripting problem in the error page for     status code 413 (CVE-2007-6203)

  - cross site scripting problem in mod_proxy_balancer     (CVE-2007-6421)

  - A flaw in mod_proxy_balancer allowed attackers to crash     apache (CVE-2007-6422)

The remote host is affected by the vulnerability described in GLSA-200803-19 (Apache: Multiple vulnerabilities)

    Adrian Pastor and Amir Azam (ProCheckUp) reported that the HTTP Method     specifier header is not properly sanitized when the HTTP return code is     '413 Request Entity too large' (CVE-2007-6203). The mod_proxy_balancer     module does not properly check the balancer name before using it     (CVE-2007-6422). The mod_proxy_ftp does not define a charset in its     answers (CVE-2008-0005). Stefano Di Paola (Minded Security) reported     that filenames are not properly sanitized within the mod_negotiation     module (CVE-2008-0455, CVE-2008-0456).
  Impact :

    A remote attacker could entice a user to visit a malicious URL or send     specially crafted HTTP requests (i.e using Adobe Flash) to perform     Cross-Site Scripting and HTTP response splitting attacks, or conduct a     Denial of Service attack on the vulnerable web server.
  Workaround :

    There is no known workaround at this time.

The version of Apache installed on the remote host is advertising a version older than 2.2.8.  Such versions may be affected by several issues, including :

 - A cross-site scripting issue involving mod_imagemap (CVE-2007-5000).

 - A cross-site scripting issue involving 413 error pages via a malformed HTTP method (PR 44014 / CVE-2007-6203).

 - A cross-site scripting issue in mod_status involving the refresh parameter (CVE-2007-6388).

 - A cross-site scripting issue in mod_proxy_balancer involving the worker route and worker redirect string of the balancer manager (CVE-2007-6421).

 - A denial of service issue in the balancer_handler function in mod_proxy_balancer can be triggered by an authenticated user when a threaded Multi-Processing Module is used (CVE-2007-6422).

 - A cross-site scripting issue using UTF-7 encoding in mod_proxy_ftp exists because it does not define a charset (CVE-2008-0005).

According to its banner, the version of Apache 2.2.x running on the remote host is prior to 2.2.8. It is, therefore, affected by the following vulnerabilities :

  - A cross-site scripting issue involving mod_imagemap     (CVE-2007-5000).

  - A cross-site scripting issue involving 413 error pages     via a malformed HTTP method (PR 44014 / CVE-2007-6203).

  - A cross-site scripting issue in mod_status involving     the refresh parameter (CVE-2007-6388).

  - A cross-site scripting issue in mod_proxy_balancer     involving the worker route and worker redirect     string of the balancer manager (CVE-2007-6421).

  - A denial of service issue in the balancer_handler     function in mod_proxy_balancer can be triggered by     an authenticated user when a threaded Multi-     Processing Module is used (CVE-2007-6422).

  - A cross-site scripting issue using UTF-7 encoding     in mod_proxy_ftp exists because it does not     define a charset (CVE-2008-0005).

Note that the remote web server may not actually be affected by these vulnerabilities. Nessus did not try to determine whether the affected modules are in use or to check for the issues themselves.

Notes: This update includes the latest release of httpd 2.2, which fixes a number of minor security issues and other bugs. A flaw was found in the mod_imagemap module. On sites where mod_imagemap was enabled and an imagemap file was publicly available, a cross-site scripting attack was possible. (CVE-2007-5000) A flaw was found in the mod_status module. On sites where mod_status was enabled and the status pages were publicly accessible, a cross- site scripting attack was possible. (CVE-2007-6388) A flaw was found in the mod_proxy_balancer module. On sites where mod_proxy_balancer was enabled, a cross-site scripting attack against an authorized user was possible. (CVE-2007-6421) A flaw was found in the mod_proxy_balancer module. On sites where mod_proxy_balancer was enabled, an authorized user could send a carefully crafted request that would cause the Apache child process handling that request to crash. This could lead to a denial of service if using a threaded Multi- Processing Module.
(CVE-2007-6422) A flaw was found in the mod_proxy_ftp module. On sites where mod_proxy_ftp was enabled and a forward proxy was configured, a cross-site scripting attack was possible against browsers which do not correctly derive the response character set following the rules in RFC 2616. (CVE-2008-0005)

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update includes the latest release of httpd 2.2, which fixes a number of minor security issues and other bugs. A flaw was found in the mod_imagemap module. On sites where mod_imagemap was enabled and an imagemap file was publicly available, a cross-site scripting attack was possible. (CVE-2007-5000) A flaw was found in the mod_status module. On sites where mod_status was enabled and the status pages were publicly accessible, a cross-site scripting attack was possible.
(CVE-2007-6388) A flaw was found in the mod_proxy_balancer module. On sites where mod_proxy_balancer was enabled, a cross-site scripting attack against an authorized user was possible. (CVE-2007-6421) A flaw was found in the mod_proxy_balancer module. On sites where mod_proxy_balancer was enabled, an authorized user could send a carefully crafted request that would cause the Apache child process handling that request to crash. This could lead to a denial of service if using a threaded Multi-Processing Module. (CVE-2007-6422) A flaw was found in the mod_proxy_ftp module. On sites where mod_proxy_ftp was enabled and a forward proxy was configured, a cross-site scripting attack was possible against browsers which do not correctly derive the response character set following the rules in RFC 2616.
(CVE-2008-0005)

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

New httpd packages are available for Slackware 12.0, and -current to fix security issues.

It was discovered that Apache did not sanitize the Expect header from an HTTP request when it is reflected back in an error message, which could result in browsers becoming vulnerable to cross-site scripting attacks when processing the output. With cross-site scripting vulnerabilities, if a user were tricked into viewing server output during a crafted server request, a remote attacker could exploit this to modify the contents, or steal confidential data (such as passwords), within the same domain. This was only vulnerable in Ubuntu 6.06. (CVE-2006-3918)

It was discovered that when configured as a proxy server and using a threaded MPM, Apache did not properly sanitize its input. A remote attacker could send Apache crafted date headers and cause a denial of service via application crash. By default, mod_proxy is disabled in Ubuntu. (CVE-2007-3847)

It was discovered that mod_autoindex did not force a character set, which could result in browsers becoming vulnerable to cross-site scripting attacks when processing the output. (CVE-2007-4465)

It was discovered that mod_imap/mod_imagemap did not force a character set, which could result in browsers becoming vulnerable to cross-site scripting attacks when processing the output. By default, mod_imap/mod_imagemap is disabled in Ubuntu. (CVE-2007-5000)

It was discovered that mod_status when status pages were available, allowed for cross-site scripting attacks. By default, mod_status is disabled in Ubuntu. (CVE-2007-6388)

It was discovered that mod_proxy_balancer did not sanitize its input, which could result in browsers becoming vulnerable to cross-site scripting attacks when processing the output. By default, mod_proxy_balancer is disabled in Ubuntu. This was only vulnerable in Ubuntu 7.04 and 7.10. (CVE-2007-6421)

It was discovered that mod_proxy_balancer could be made to dereference a NULL pointer. A remote attacker could send a crafted request and cause a denial of service via application crash. By default, mod_proxy_balancer is disabled in Ubuntu. This was only vulnerable in Ubuntu 7.04 and 7.10. (CVE-2007-6422)

It was discovered that mod_proxy_ftp did not force a character set, which could result in browsers becoming vulnerable to cross-site scripting attacks when processing the output. By default, mod_proxy_ftp is disabled in Ubuntu. (CVE-2008-0005).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to its banner, the version of Apache 2.2 installed on the remote host is older than 2.2.9.  Such versions may be affected by several issues, including :

  - Improper handling of excessive forwarded interim responses may cause denial of service conditions in mod_proxy_http (CVE-2008-2364).
  - A cross-site request forgery vulnerability in the balancer-manager interface of mod_proxy_balancer (CVE-2007-6420).
  - An issue exists in the handling of the 'Options' and 'AllowOverride' directives (CVE-2009-1195).

Note that the remote web server may not actually be affected by these vulnerabilities.  NNM cannot determine whether the affected modules are in use.

According to its banner, the version of Apache 2.2 installed on the remote host is older than 2.2.9.  Such versions may be affected by several issues, including :

  - Improper handling of excessive forwarded interim responses may cause denial of service conditions in mod_proxy_http (CVE-2008-2364).
  - A cross-site request forgery vulnerability in the balancer-manager interface of mod_proxy_balancer (CVE-2007-6420).
  - An issue exists in the handling of the 'Options' and 'AllowOverride' directives (CVE-2009-1195).

Note that the remote web server may not actually be affected by these vulnerabilities.

ID	Name	Product	Family	Severity
67633	Oracle Linux 5 : Moderate: / httpd (ELSA-2008-0008)	Nessus	Oracle Linux Local Security Checks	medium
60345	Scientific Linux Security Update : httpd on SL3.x, SL4.x, SL5.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	medium
43666	CentOS 5 : httpd (CESA-2008:0008)	Nessus	CentOS Local Security Checks	medium
36524	Mandriva Linux Security Advisory : apache (MDVSA-2008:016)	Nessus	Mandriva Local Security Checks	medium
31768	SuSE 10 Security Update : Apache 2 (ZYPP Patch Number 5128)	Nessus	SuSE Local Security Checks	medium
31767	openSUSE 10 Security Update : apache2 (apache2-5127)	Nessus	SuSE Local Security Checks	medium
31766	openSUSE 10 Security Update : apache2 (apache2-5126)	Nessus	SuSE Local Security Checks	medium
31765	openSUSE 10 Security Update : apache2 (apache2-5125)	Nessus	SuSE Local Security Checks	medium
31445	GLSA-200803-19 : Apache: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	medium
4385	Apache < 2.2.8 Multiple Vulnerabilities	Nessus Network Monitor	Web Servers	high
31118	Apache 2.2.x < 2.2.8 Multiple Vulnerabilities (XSS, DoS)	Nessus	Web Servers	medium
31105	Fedora 7 : httpd-2.2.8-1.fc7 (2008-1711)	Nessus	Fedora Local Security Checks	medium
31103	Fedora 8 : httpd-2.2.8-1.fc8 (2008-1695)	Nessus	Fedora Local Security Checks	medium
31099	Slackware 12.0 / current : httpd (SSA:2008-045-01)	Nessus	Slackware Local Security Checks	medium
30184	Ubuntu 6.06 LTS / 6.10 / 7.04 / 7.10 : apache2 vulnerabilities (USN-575-1)	Nessus	Ubuntu Local Security Checks	medium
29977	RHEL 5 : httpd (RHSA-2008:0008)	Nessus	Red Hat Local Security Checks	medium
4579	Apache < 2.2.9 Multiple Vulnerabilities	Nessus Network Monitor	Web Servers	high
800581	Apache < 2.2.8 Multiple Vulnerabilities	Log Correlation Engine	Web Servers	low
800558	Apache < 2.2.9 Multiple Vulnerabilities	Log Correlation Engine	Web Servers	medium

Detections

Analytics

CVE-2007-6422

medium

Tenable Plugins

medium

medium

medium

medium

medium

medium

medium

medium

medium

high

medium

medium

medium

medium

medium

medium

high

low

medium