CVE-2021-31878

MEDIUM
Published Jul 30, 20214y ago · Modified Jun 17, 20262w ago
6.5 CVSS 3.1
Medium
Find Similar
Published Jul 30, 2021 4y ago
Last Modified Jun 17, 2026 2w ago

Description

An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re-INVITE without SDP must be received after Asterisk has sent a BYE request.

CVSS Details

Base Score
6.5
Exploitability
2.8
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required Low
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
Public Exploit Known
Patch Available

Weaknesses 1

CWE-617

Affected Products 6

VendorProductVersionRange
digiumasterisk16.17.0any
digiumasterisk16.18.0any
digiumasterisk16.19.0any
digiumasterisk18.3.0any
digiumasterisk18.4.0any
digiumasterisk18.5.0any

References 5

  • downloads.asterisk.org http://downloads.asterisk.org/pub/security/AST-2021-007.html
    PatchVendor Advisory
  • packetstormsecurity.com http://packetstormsecurity.com/files/163638/Asterisk-Project-Security-Advisory-AST-2021-007.html
    PatchThird Party AdvisoryVDB Entry
  • seclists.org http://seclists.org/fulldisclosure/2021/Jul/48
    Mailing ListPatchThird Party Advisory
  • downloads.digium.com https://downloads.digium.com/pub/security/AST-2021-007.html
    PatchVendor Advisory
  • issues.asterisk.org https://issues.asterisk.org/jira/browse/ASTERISK-29381
    ExploitIssue TrackingVendor Advisory

Remediation

  • downloads.asterisk.org http://downloads.asterisk.org/pub/security/AST-2021-007.html
    PatchVendor Advisory
  • packetstormsecurity.com http://packetstormsecurity.com/files/163638/Asterisk-Project-Security-Advisory-AST-2021-007.html
    PatchThird Party AdvisoryVDB Entry
  • seclists.org http://seclists.org/fulldisclosure/2021/Jul/48
    Mailing ListPatchThird Party Advisory
  • downloads.digium.com https://downloads.digium.com/pub/security/AST-2021-007.html
    PatchVendor Advisory