CVE-2008-2499: IBM Lotus Sametime MUX stack buffer overflow via crafted URL

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 18 September 2026. Confidence: high.

high priorityRemote unauthenticated code execution with a very high EPSS score and public exploit reference, though not in KEV.

What it is

The Community Services Multiplexer (StMux.exe) in IBM Lotus Sametime 7.5.1 CF1 and earlier, and 8.x before 8.0.1, contains a stack-based buffer overflow (CWE-119) triggered by a crafted URL. A remote, unauthenticated attacker can exploit this to execute arbitrary code on the affected system.

Impact

Successful exploitation allows remote code execution with the privileges of the vulnerable service, potentially leading to full compromise of the host. The CVSS 2.0 vector (AV:N/AC:L/Au:N/C:P/I:P/A:P) indicates partial confidentiality, integrity, and availability impact.

Attack surface

The flaw is reachable over the network via a crafted URL processed by the MUX component; no authentication is required per the CVSS vector (Au:N). No user interaction is indicated in the description or vector.

Exploitation

The record is not listed in CISA KEV, but EPSS is very high (0.77466, 99.5th percentile) and a reference is tagged 'Exploit', indicating public exploit information exists. No ransomware associations are documented.

What to do

• Apply the vendor patch or upgrade to IBM Lotus Sametime 8.0.1 or later as directed by IBM advisory swg21303920.
• If immediate patching is not possible, restrict network access to the MUX service (StMux.exe) to trusted hosts only.
• Monitor and filter crafted URLs directed at the Sametime MUX component at network boundaries.
• Review IBM's advisory and any available workarounds for interim risk reduction.

Detection

• Inspect network traffic for malformed or unusually long URLs targeting the Sametime MUX service.
• Monitor host logs for crashes or abnormal process behavior in StMux.exe.
• Use endpoint detection to flag buffer overflow exploitation patterns (e.g., unexpected code execution from the MUX process).

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.