CVE-2023-31122

Deeper analysis

CVE-2023-31122 is an out-of-bounds read vulnerability, tracked as CWE-125, that affects the mod_macro module in Apache HTTP Server versions through 2.4.57. The flaw carries a CVSS 3.1 score of 7.5 with a vector indicating network attackability, low complexity, and no required privileges or user interaction, resulting in high availability impact while leaving confidentiality and integrity unaffected.

Remote attackers can trigger the flaw over the network to induce a denial-of-service condition against an unpatched server. Because the vulnerability requires no authentication or special conditions beyond sending crafted requests, any internet-facing Apache instance running an affected version is potentially reachable.

The Apache project has published details at httpd.apache.org/security/vulnerabilities_24.html, and downstream distributions including Debian and Fedora have issued coordinated advisories that direct administrators to apply the corresponding package updates.

EPSS for the CVE rose from a low baseline to a peak of 0.0574 on 2025-01-22 before receding to the current value of 0.0040, indicating a period of increased exploitation interest well after initial disclosure.