CVE-2021-26717

HIGH
Published Feb 18, 20215y ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Feb 18, 2021 5y ago
Last Modified Jun 17, 2026 2w ago

Description

An issue was discovered in Sangoma Asterisk 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6. When re-negotiating for T.38, if the initial remote response was delayed just enough, Asterisk would send both audio and T.38 in the SDP. If this happened, and the remote responded with a declined T.38 stream, then Asterisk would crash.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 16

VendorProductVersionRange
digiumasterisk*≥16.0.0  –  <16.16.1
digiumasterisk*≥17.0.0  –  <17.9.2
digiumasterisk*≥18.0  –  <18.2.1
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any
digiumcertified_asterisk16.8any

References 5

  • packetstormsecurity.com http://packetstormsecurity.com/files/161471/Asterisk-Project-Security-Advisory-AST-2021-002.html
    Third Party Advisory
  • seclists.org http://seclists.org/fulldisclosure/2021/Feb/58
    Mailing ListPatchThird Party Advisory
  • downloads.asterisk.org https://downloads.asterisk.org/pub/security/
    Vendor Advisory
  • downloads.asterisk.org https://downloads.asterisk.org/pub/security/AST-2021-002.html
    Vendor Advisory
  • issues.asterisk.org https://issues.asterisk.org/jira/browse/ASTERISK-29203
    Issue TrackingPatchVendor Advisory

Remediation

  • seclists.org http://seclists.org/fulldisclosure/2021/Feb/58
    Mailing ListPatchThird Party Advisory
  • issues.asterisk.org https://issues.asterisk.org/jira/browse/ASTERISK-29203
    Issue TrackingPatchVendor Advisory