Vulnerability Monitor

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CVE-2021-37706


PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In affected versions if the incoming STUN message contains an ERROR-CODE attribute, the header length is not checked before performing a subtraction operation, potentially resulting in an integer underflow scenario. This issue affects all users that use STUN. A malicious actor located within the victim’s network may forge and send a specially crafted UDP (STUN) message that could remotely execute arbitrary code on the victim’s machine. Users are advised to upgrade as soon as possible. There are no known workarounds.


Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.3, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts limited data confidentiality, limited integrity, and limited availability for affected systems. Impacting 4 products from teluu, from asterisk, from sangoma and 1 other, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2021-12-22T18:15:07.487

Last Modified

2025-11-04T16:15:43.010

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.3 (HIGH)

CVSSv2 Vector

AV:N/AC:M/Au:N/C:C/I:C/A:C

  • Access Vector: NETWORK
  • Access Complexity: MEDIUM
  • Authentication: NONE
  • Confidentiality Impact: COMPLETE
  • Integrity Impact: COMPLETE
  • Availability Impact: COMPLETE
Exploitability Score

8.6

Impact Score

10.0

Weaknesses
  • Type: Secondary
    CWE-191
  • Type: Primary
    CWE-191

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application teluu pjsip ≤ 2.11.1 Yes
Application asterisk certified_asterisk < 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application asterisk certified_asterisk 16.8.0 Yes
Application sangoma asterisk < 16.24.1 Yes
Application sangoma asterisk < 18.10.1 Yes
Application sangoma asterisk < 19.2.1 Yes
Operating System debian debian_linux 9.0 Yes
Operating System debian debian_linux 10.0 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For teluu's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.