CVE-2016-9937
CWE-119Published: December 12, 2016· Updated: Jun 17, 2026
Official Description
An issue was discovered in Asterisk Open Source 13.12.x and 13.13.x before 13.13.1 and 14.x before 14.2.1. If an SDP offer or answer is received with the Opus codec and with the format parameters separated using a space the code responsible for parsing will recursively call itself until it crashes. This occurs as the code does not properly handle spaces separating the parameters. This does NOT require the endpoint to have Opus configured in Asterisk. This also does not require the endpoint to be authenticated. If guest is enabled for chan_sip or anonymous in chan_pjsip an SDP offer or answer is still processed and the crash occurs.
Technical Analysis
CVE-2016-9937 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.
From a weakness classification perspective (CWE-119): Buffer overflow vulnerabilities can lead to arbitrary code execution or denial of service by corrupting adjacent memory.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (12)
Quick Facts
Related CVEs (CWE-119)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2016-9937 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts