CVE-2020-28327: n/a vulnerability

CVE-2020-28327: A res_pjsip_session crash was discovered in Asterisk Open Source 13.x before 13.37.1, 16.x before 16.14.1,...

A res_pjsip_session crash was discovered in Asterisk Open Source 13.x before 13.37.1, 16.x before 16.14.1, 17.x before 17.8.1, and 18.x before 18.0.1. and Certified Asterisk before 16.8-cert5. Upon receiving a new SIP Invite, Asterisk did not return the created dialog locked or referenced. This caused a gap between the creation of the dialog object, and its next use by the thread that created it. Depending on some off-nominal circumstances and timing, it was possible for another thread to free said dialog in this gap. Asterisk could then crash when the dialog object, or any of its dependent objects, were dereferenced or accessed next by the initial-creation thread. Note, however, that this crash can only occur when using a connection-oriented protocol (e.g., TCP or TLS, but not UDP) for SIP transport. Also, the remote client must be authenticated, or Asterisk must be configured for anonymous calling.

UnknownCVSS not scoredNot KEV-listedUpdatedAug 4, 2024, 16:33 UTC (UTC+00:00)

Security readout for executives and security teams

Certain Asterisk systems could crash when processing a new SIP INVITE over TCP or TLS. The issue is a race condition in dialog handling, so the primary business impact is voice service interruption rather than data theft. Exposure is most likely where affected Asterisk Open Source or Certified Asterisk versions use SIP over TCP or TLS, especially with authenticated remote clients or anonymous calling enabled. Treat as a service availability risk for phone infrastructure. Prioritize upgrades where Asterisk accepts SIP over TCP or TLS from remote or semi-trusted clients. Mitigation focus: Upgrade Asterisk Open Source to 13.37.1, 16.14.1, 17.8.1, 18.0.1, or later.; Upgrade Certified Asterisk to 16.8-cert5 or later.; Review vendor advisory AST-2020-001 for environment-specific guidance..

Prepared: Jun 5, 2026, 13:31 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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Vulnerability profileCVE Program record

Severity: Unknown
CVSS: Not scored
Known Exploited: No
Published: Nov 6, 2020, 18:08 UTC (UTC+00:00)

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors

0Timeline events

0ADP providers

2Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

CVE List V5 sourceCVE List V5
https://issues.asterisk.org/jira/browse/ASTERISK-29057CVE reference · x_refsource_MISC

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus

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Weakness

CWE details

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