Asterisk can crash from a specifically malformed Authorization header in an incoming SIP request
Asterisk is an open source private branch exchange and telephony toolkit. Prior to versions 20.15.2, 21.10.2, and 22.5.2, if a SIP request is received with an Authorization header that contains a realm that wasn't in a previous 401 response's WWW-Authenticate header, or an Authorization header with an incorrect realm was received without a previous 401 response being sent, the get_authorization_header() function in res_pjsip_authenticator_digest will return a NULL. This wasn't being checked before attempting to get the digest algorithm from the header which causes a SEGV. This issue has been patched in versions 20.15.2, 21.10.2, and 22.5.2. There are no workarounds.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for help- Published
- Aug 28, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.4% · 32th percentile
- CWE
- CWE-253
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Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 7.5
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| sangoma | asterisk | cpe:2.3:a:sangoma:asterisk |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- sangoma asteriskbefore 20.15.2
- sangoma asterisk21.0.0 and later · before 21.10.2
- sangoma asterisk22.0.0 and later · before 22.5.2
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
asterisk asterisk
- < 22.5.2, < 21.10.2, < 20.15.2affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:14 | asterisk | before 1:22.5.2~dfsg+~cs6.15.60671435-1 | 1:22.5.2~dfsg+~cs6.15.60671435-1 |
Same product
sangoma: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-57520Insecure Permissions vulnerability in asterisk v22 allows a remote attacker to execute arbitrary code via the action_createconfig function.39Monitor
- CVE-2026-23741ast_coredumper running as root sources ast_debug_tools.conf from /etc/asterisk; potentially leading to privilege escalation35Monitor
- CVE-2022-37325In Sangoma Asterisk through 16.28.0, 17.x and 18.x through 18.14.0, and 19.x through 19.6.0, an incoming Setup message to addons/ooh323c/src30Monitor
- CVE-2009-3723asterisk allows calls on prohibited networks30Monitor
- CVE-2025-1131Asterisk Unsafe Shell Sourcing in safe_asterisk Leads to Local Privilege Escalation28Monitor
- CVE-2018-12228An issue was discovered in Asterisk Open Source 15.x before 15.4.1.28Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:asterisk | 1:22.5.2~dfsg+~cs6.15.60671435-1 · Debian:14 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-253 · Incorrect Check of Function Return ValueCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/asterisk/asterisk/commit/02993717b08f899d4aca9888062f35dfb198584f
- github.com/asterisk/asterisk/pull/1407
- github.com/asterisk/asterisk/security/advisories/GHSA-64qc-9x89-rx5j
Vendor advisories and official records. Exploit/PoC links are deliberately left out.