pjproject: Use After Free
CVE-2022-23608 is a critical-severity use after free vulnerability in pjproject from Pjsip, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected pjproject versions: <= 2.11.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 4.02% chance of exploitation within 30 days, which is in the top 9.25% of all scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Certified Asterisk to 16.8.0 or a later version.
- Update Asterisk to 16.24.1 or 18.10.1 or 19.2.1, whichever matches your release line, or a later version.
- Read the advisory on packetstormsecurity.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Pjsip | pjproject | <= 2.11.1 | Not stated |
| Teluu | Pjsip | 2.11.1 and earlier | Not stated |
| Asterisk | Certified Asterisk | before 16.8.0; 16.8.0 | 16.8.0 |
| Sangoma | Asterisk | 16.0.0 up to, but not including, 16.24.1; 18.0.0 up to, but not including, 18.10.1; 19.0.0 up to, but not including, 19.2.1 | 16.24.1, 18.10.1, 19.2.1 |
| Debian | Debian Linux | 9.0; 10.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.1 | High | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 2.0 | 7.5 | High | NVD |
Official 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: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
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.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- packetstormsecurity.com/files/166226/Asterisk-Project-Security-Advisory-AST-2022-005.htmlThird Party Advisory, VDB Entry
- github.com/pjsip/pjproject/security/advisories/GHSA-ffff-m5fm-qm62Issue Tracking, Third Party Advisory
Patches and release notes
- seclists.org/fulldisclosure/2022/Mar/1Mailing List, Third Party Advisory
- github.com/pjsip/pjproject/commit/db3235953baa56d2fb0e276ca510fefca751643fThird Party Advisory
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2022/03/msg00035.htmlMailing List, Third Party Advisory
- lists.debian.org/debian-lts-announce/2022/03/msg00040.htmlMailing List, Third Party Advisory
- lists.debian.org/debian-lts-announce/2022/11/msg00021.htmlMailing List, Third Party Advisory
- security.gentoo.org/glsa/202210-37Third Party Advisory
- debian.org/security/2022/dsa-5285Third Party Advisory
Other references
Other vulnerabilities in pjproject
- 7.4 High severity
- 7.1 High severity
- 9.1 Critical severity
- 9.1 Critical severity
- 8.2 High severity
- 7.5 High severity
Recent Use After Free vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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