Finding and Fixing Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation , a Medium Risk Vulnerability

With Notes on Remediation, Penetration Testing, Disclosures, Patching and Exploits

Contents

  • Vital information on this issue
  • Scanning For and Finding Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation
  • Penetration Testing (Pentest) for this Vulnerability
  • Security updates on Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation
  • Disclosures related to Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation
  • Confirming the Presence of Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation
  • False positive/negatives
  • Patching/Repairing this vulnerability
  • Exploits related to Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation

Vital Information on This Issue
Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation is a Medium risk vulnerability that is one of the most frequently found on networks around the world. This issue has been around since at least 1990 but has proven either difficult to detect, difficult to resolve or prone to being overlooked entirely.


Vulnerability Name: Apache mod_suexec Multiple Privilege Escalation
Test ID: 13984
Risk: Medium
Category: Web servers
Type: Attack
Summary: Multiple vulnerabilities have been found in Apache mod_suexec: * Multiple race conditions in suexec in Apache HTTP Server (httpd) 2.2.3 between directory and file validation, and their usage, allow local users to gain privileges and execute arbitrary code by renaming directories or performing symlink attacks. NOTE: the researcher, who is reliable, claims that the vendor disputes the issue because "the attacks described rely on an insecure server configuration" in which the user "has write access to the document root."


* suexec in Apache HTTP Server (httpd) 2.2.3 uses a partial comparison for verifying whether the current directory is within the document root, which might allow local users to perform unauthorized operations on incorrect directories, as demonstrated using "html_backup" and "htmleditor" under an "html" directory. NOTE: the researcher, who is reliable, claims that the vendor disputes the issue because "the attacks described rely on an insecure server configuration" in which the user "has write access to the document root."

* suexec in Apache HTTP Server (httpd) 2.2.3 does not verify combinations of user and group IDs on the command line, which might allow local users to leverage other vulnerabilities to create arbitrary UID/GID owned files if /proc is mounted. NOTE: the researcher, who is reliable, claims that the vendor disputes the issue because "the attacks described rely on an insecure server configuration" in which the user "has write access to the document root." In addition, because this is dependent on other vulnerabilities, perhaps this is resultant and should not be included in CVE.
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Impact: The attacks described rely on an insecure server configuration in which the user has write access to the document root.
Solution: Disable suexec or disallow users from writing to the document root.
CVE: CVE-2007-1741

CVE-2007-1742

CVE-2007-1743

More Information: http://marc.info/?l=apache-httpd-dev&m=117511568709063&w=2

http://marc.info/?l=apache-httpd-dev&m=117511834512138&w=2

http://www.securiteam.com/unixfocus/5HP0D0KL5K.html

http://www.securityfocus.com/bid/23438/discuss

ftp://ftp.netbsd.org/pub/pkgsrc/current/pkgsrc/www/apache24/README.html

Nist NVD (CVSS): AV:L/AC:H/Au:N/C:C/I:C/A:C
CVSS Score: 6.2
For more information on this also issue see: www.securiteam.com

Scanning For and Finding Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation
Use of Vulnerability Management tools, like AVDS, are standard practice for the discovery of this vulnerability. The primary failure of VA in finding this vulnerability is related to setting the proper scope and frequency of network scans. It is vital that the broadest range of hosts (active IPs) possible are scanned and that scanning is done frequently. We recommend weekly. Your existing scanning solution or set of test tools should make this not just possible, but easy and affordable. If that is not the case, please consider AVDS.

Penetration Testing (pentest) for this Vulnerability
The Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation is prone to false positive reports by most vulnerability assessment solutions. AVDS is alone in using behavior based testing that eliminates this issue. For all other VA tools security consultants will recommend confirmation by direct observation. In any case Penetration testing procedures for discovery of Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation produces the highest discovery accuracy rate, but the infrequency of this expensive form of testing degrades its value. The ideal would be to have pentesting accuracy and the frequency and scope possibilities of VA solutions, and this is accomplished only by AVDS.

Security Updates on Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation
For the most current updates on this vulnerability please check www.securiteam.com Given that this is one of the most frequently found vulnerabilities, there is ample information regarding mitigation online and very good reason to get it fixed. Hackers are also aware that this is a frequently found vulnerability and so its discovery and repair is that much more important. It is so well known and common that any network that has it present and unmitigated indicates "low hanging fruit" to attackers.

Disclosures related to this vulnerability

Confirming the Presence of Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation
AVDS is currently testing for and finding this vulnerability with zero false positives. If your current set of tools is indicating that it is present but you think it is probably a false positive, please contact us for a demonstration of AVDS.

False positive/negatives
The secret killer of VA solution value is the false positive. There was an industry wide race to find the most vulnerabilities, including Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation ,and this resulted in benefit to poorly written tests that beef up scan reports by adding a high percentage of uncertainty. This may have sold a lot of systems some years ago, but it also stuck almost all VA solutions with deliberately inaccurate reporting that adds time to repairs that no administrator can afford. Beyond Security did not participate in this race to mutually assured destruction of the industry and to this day produces the most accurate and actionable reports available.

Patching/Repairing this Vulnerability

Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation is a Medium risk vulnerability that is also high frequency and high visibility. This is the most severe combination of security factors that exists and it is extremely important to find it on your network and fix it as soon as possible.

Exploits related to Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation
https://vuldb.com/?id.36164
https://www.exploit-db.com/papers/12906/
https://packetstormsecurity.com/search/files/?q=kingcope

Please also visit www.securiteam.com to view any exploits available for this vulnerability, or search using "Vulnerabilities in Apache mod_suexec Multiple Privilege Escalation ".


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