CVE-2024-23839: 
Suricata vulnerability analysis and mitigation

CVE-2024-23839 affects Suricata, a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. The vulnerability was discovered in versions prior to 7.0.3, where specially crafted traffic can trigger a heap use-after-free condition when the ruleset uses the http.request_header or http.response_header keyword (GHSA Advisory).

The vulnerability is classified as a heap use-after-free (CWE-416) issue. The problem occurs when multiple inspection buffer instances point to the same memory address from HttpHeaderGetBufferSpace, which is not owned by the transaction. When headers are rebuilt, the memory can be reallocated if one header exceeds 1024 bytes, while the previously freed pointer continues to be used for previous headers (Suricata Commit). The vulnerability has received a CVSS v3.1 base score of 8.1 HIGH (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H) from NVD, and 7.1 HIGH (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H) from GitHub (NVD).

The vulnerability can lead to a heap use-after-free condition when processing HTTP headers, potentially resulting in denial of service or other security implications. The issue affects systems using http.request_header or http.response_header keywords in their ruleset (GHSA Advisory).

The vulnerability has been patched in Suricata version 7.0.3. As a workaround, users can avoid using the http.request_header and http.response_header keywords in their rulesets. Fedora has released security updates for affected versions in Fedora 38 and 39 (Fedora Update).