Tech Stack: Apache HTTP Server (httpd)

Date(s) Issued: Published: 03/26/2018; Last Modified: 12/03/2024

Criticality: CVSS v2 Score: 5.0 – MEDIUM

Overview: CVE-2018-1303 is an out-of-bounds read vulnerability in the mod_cache_socache module of Apache HTTP Server versions prior to 2.4.30. A specially crafted HTTP request header can trigger this flaw, leading to a server crash due to an out-of-bounds read while preparing data to be cached in shared memory. This vulnerability can be exploited to cause a Denial of Service (DoS) attack against servers utilizing mod_cache_socache. The risk is considered low since mod_cache_socache is not widely used, and the commonly used mod_cache_disk is not affected by this vulnerability.

Solution/Mitigation:

1. Upgrade Apache HTTP Server:
   • Version: Upgrade to Apache HTTP Server version 2.4.30 or later, where this vulnerability has been addressed. Ensure that all instances of the server are updated to prevent potential exploitation.
2. Disable mod_cache_socache Module (if not in use):
   • Configuration: If your server does not require the mod_cache_socache module, disable it to eliminate the attack vector. This can be done by commenting out or removing the line that loads the module in your Apache configuration files, typically:shellCopy code#LoadModule cache_socache_module modules/mod_cache_socache.so
   • Restart Server: After making configuration changes, restart the Apache HTTP Server to apply them.
3. Monitor Server Logs:
   • Log Analysis: Regularly review server logs for unusual activities, such as malformed HTTP request headers that could indicate attempts to exploit this vulnerability. Implement automated alerts for such anomalies to facilitate prompt investigation.
4. Apply Security Patches:
   • Operating System Updates: Ensure your operating system and all installed packages are up to date with the latest security patches provided by your distribution. For instance, Debian has addressed this issue in DSA-4164.

Confirmation & Additional Information:

• Verification: After applying the upgrade or configuration changes, test the server to confirm that the vulnerability has been mitigated. Attempt to send specially crafted HTTP request headers to ensure they no longer cause a server crash.
• Stay Updated: Regularly consult official Apache HTTP Server security advisories and your operating system’s security bulletins to stay informed about any new vulnerabilities or patches. Subscribe to relevant mailing lists or RSS feeds for timely notifications.
• Official Resources:
  • National Vulnerability Database Entry: NVD
  • Debian Security Tracker: CVE Details