Use after free in PJSIP (CVE-2022-23608)
Published Sources: Debian, CVE.org
What is affected, what to do
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 versions up to and including 2.11.1 when in a dialog set (or forking) scenario, a hash key shared by multiple UAC dialogs can potentially be prematurely freed when one of the dialogs is destroyed .
An exploit is publicly available. Update certified_asterisk to version 16.8.0, asterisk to version 19.2.1.
- Affected
- Pjsip Pjproject
lte *..2.11.1
- Pjsip Pjproject
Not sure whether and how you are affected? Ask a question about this vulnerability
Metrics
9.8
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
8.1
CVSS v3
Severity High on the scale from 0 to 10.
Source: Debian, CVE.org
4.0 %
EPSS score
Moderate — model estimates 1-10% exploitation likelihood.
Source: FIRST EPSS, percentile 90.5
Show all metrics
- Severity
- Critical
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 106.55 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- PoC (publicly reported)
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 9.8 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 8.1
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 4.0 %
- Moderate — model estimates 1-10% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 90.5
- Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
- CISA assessment (SSVC)
- Exploitation: none known · not automatable · Technical impact: total
- Source: CISA Vulnrichment, as of 23 April 2025
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-416
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
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 versions up to and including 2.11.1 when in a dialog set (or forking) scenario, a hash key shared by multiple UAC dialogs can potentially be prematurely freed when one of the dialogs is destroyed . The issue may cause a dialog set to be registered in the hash table multiple times (with different hash keys) leading to undefined behavior such as dialog list collision which eventually leading to endless loop. A patch is available in commit db3235953baa56d2fb0e276ca510fefca751643f which will be included in the next release. There are no known workarounds for this issue.
Source: Debian Security Advisories, NVD (NIST), cvelistv5
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| pjsip | pjproject |
|
|
| asterisk | certified_asterisk |
|
|
| sangoma | asterisk |
|
|
| teluu | pjsip |
|
|
Vendors and products
Affected operating systems
| Linux | debian | asterisk | bullseye |
| Linux | debian | debian_linux | 10.0 |
| Linux | debian | debian_linux | 9.0 |
Weakness classes (CWE)
CWE-416Use After Free
Variant
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Entry at MITRE CWE-416
Public exploit references
Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.
| Packet Storm | Asterisk Project Security Advisory AST 2022 005 (opens in a new tab)packetstormsecurity.com | PoC (publicly reported)reported, not verified | — |
References & sources
- github.compjsip/pjproject/security/advisories/GHSA-ffff-m5fm-qm62Issue tracking, Patch, Third-party advisory
- github.compjsip/pjproject/commit/db3235953baa56d2fb0e276ca510fefca751643fPatch, Third-party advisory
- seclists.org20220304 AST-2022-005: pjproject: undefined behavior after freeing a dialog setMailing list, Mailing list, Patch, Third-party advisory
- packetstormsecurity.comfiles/166226/Asterisk-Project-Security-Advisory-AST-2022-005.ht…Third-party advisory, Vulnerability database
- lists.debian.org[debian-lts-announce] 20220328 [SECURITY] [DLA 2962-1] pjproject security updateMailing list, Mailing list, Third-party advisory
- lists.debian.org[debian-lts-announce] 20220331 [SECURITY] [DLA 2962-2] pjproject regression updateMailing list, Mailing list, Third-party advisory
- security.gentoo.orgGLSA-202210-37Vendor advisory, Third-party advisory
- lists.debian.org[debian-lts-announce] 20221117 [SECURITY] [DLA 3194-1] asterisk security updateMailing list, Mailing list, Third-party advisory
- debian.orgDSA-5285Vendor advisory, Third-party advisory
- lists.debian.org[debian-lts-announce] 20230829 [SECURITY] [DLA 3549-1] ring security updateMailing list
- lists.debian.orgdebian-lts-announce/2024/09/msg00030.html
Embed badge
Show the severity and KEV status of this vulnerability on your site – with a link back here. The image is updated hourly.
<a href="https://intel.neosec.eu/en/cve/CVE-2022-23608"><img src="https://intel.neosec.eu/badge/cve/CVE-2022-23608.svg?lang=en" alt="CVE-2022-23608 – NEOSEC Intel" height="20"></a>