The RTSP handler in libalias rewrote outgoing packets into a fixed-length stack buffer without checking whether the rewritten data fit in the buffer,...
Description
The RTSP handler in libalias rewrote outgoing packets into a fixed-length stack buffer without checking whether the rewritten data fit in the buffer, or whether the result fit back in the original packet
AI Analyst Comment
Remediation
Apply vendor security updates immediately. Monitor for exploitation attempts and review access logs.
---METADATA---
VENDOR: FreeBSD
PRODUCT: FreeBSD
AFFECTED_VERSIONS: 15.1-RELEASE (before p1), 15.0-RELEASE (before p11), 14.4-RELEASE (before p7), 14.3-RELEASE (before p16)
CONFIDENCE: high
MISSING: patch
---END_METADATA---
Description Summary:
A stack-based buffer overflow in the FreeBSD libalias RTSP handler allows for memory corruption due to missing length checks when rewriting outgoing packets.
Executive Summary:
A stack-based buffer overflow in the FreeBSD libalias component could lead to arbitrary code execution or system instability when processing malformed RTSP packets.
Vulnerability Details
CVE-ID: CVE-2026-49420
Affected Software: FreeBSD FreeBSD
Affected Versions: 15.1-RELEASE (before p1), 15.0-RELEASE (before p11), 14.4-RELEASE (before p7), 14.3-RELEASE (before p16)
Vulnerability: The vulnerability is a stack-based buffer overflow (CWE-121) located in the libalias RTSP handler. It occurs because the software fails to validate if rewritten packet data fits within the allocated stack buffer, allowing an unauthenticated attacker on the local network segment (AV:A) to trigger a memory corruption event.
Business Impact
Successful exploitation results in significant security impact, including potential remote code execution and system crashes. Given the CVSS score of 8.8, this vulnerability poses a severe threat to infrastructure stability and data confidentiality for any organization relying on FreeBSD libalias for packet processing.
Remediation Plan
Immediate Action: Apply the vendor security updates provided in FreeBSD-SA-26:41.libalias to all affected release versions immediately.
Proactive Monitoring: Monitor network traffic for malformed RTSP packets or unusual spikes in system crashes related to the libalias component.
Compensating Controls: Deploy firewall rules to restrict access to RTSP services and ensure that only authorized traffic is allowed to reach vulnerable network interfaces.
Exploitation Status
Public Exploit Available: Unknown
Analyst Notes: As of August 20, 2026, there is no public information indicating active exploitation or a public proof-of-concept for this vulnerability. While the exploit requires local network access, the nature of the flaw as a buffer overflow makes it a prime target for weaponization.
Analyst Recommendation
FreeBSD administrators should treat this vulnerability with high urgency due to the risk of memory corruption and potential code execution. Updating to the patched releases identified in the security advisory is the only effective way to remediate this flaw and ensure the continued security of the FreeBSD environment.