Reflected cross-site scripting in Asterisk phone provisioning pages
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
Asterisk and Certified Asterisk are affected in phone provisioning HTTP error pages when res_phoneprov is enabled, caused by improper neutralization of input (CWE-79). An unauthenticated remote attacker can use reflected cross-site scripting to retrieve an authorized user's AMI session cookie and impersonate that user, if the user clicks a malicious link. The Asterisk HTTP server, AMI and AMI access via HTTP must all be enabled for the flaw to be reachable.
Written with Claude Haiku 5.5 from the sources below · 2026-11-02
Description from the CNA
Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3, an unauthenticated attacker may use reflected cross-site scripting in `phone provisioning HTTP error pages` to retrieve an authorized user's `AMI session cookie` and impersonate that user when `res_phoneprov` is enabled. The Asterisk HTTP web server, Asterisk Manager Interface (AMI), and AMI access via HTTP must all be enabled; each is disabled by default. The attacker must be able to connect to the HTTP server, which binds only to `127.0.0.1` by default even when enabled, and must convince the authorized user to click a malicious link. This issue is fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| asterisk | asterisk | before 20.20.1; 21.0.0-pre1 to before 21.12.3; 22.0.0-pre1 to before 22.10.1; 23.0.0-pre1 to before 23.4.1 | 20.20.1, 21.12.3, 22.10.1, 23.4.1 | Patch available | CNA |
| asterisk | certified-asterisk | before 20.7-cert11; 22.8-cert1-pre1 to before 22.8-cert3 | 20.7-cert11, 22.8-cert3 | Patch available | CNA |
- asterisk Vendorasterisk Affected before 20.20.1; 21.0.0-pre1 to before 21.12.3; 22.0.0-pre1 to before 22.10.1; 23.0.0-pre1 to before 23.4.1 Fixed in 20.20.1, 21.12.3, 22.10.1, 23.4.1 Patch available CNA
- certified-asterisk Vendorasterisk Affected before 20.7-cert11; 22.8-cert1-pre1 to before 22.8-cert3 Fixed in 20.7-cert11, 22.8-cert3 Patch available CNA
Remediation
Upgrade Asterisk to 20.20.1, 21.12.3, 22.10.1 or 23.4.1, and Certified Asterisk to 20.7-cert11 or 22.8-cert3, which fix this issue.
Written with Claude Haiku 5.5 from the sources below · 2026-11-02
- Fix · CNA asterisk (asterisk) Fixed in 20.20.1, 21.12.3, 22.10.1, 23.4.1
- Fix · CNA certified-asterisk (asterisk) Fixed in 20.7-cert11, 22.8-cert3
Vendor assessments
Timeline
- 2026-10-26 Threatist record created from CVE-2026-57196
- 2026-10-26 CISA SSVC decision points changed
- 2026-11-02 Affected versions changed · Red Hat
- 2026-11-02 CVSS score added · Red Hat
References
Other 15
- https://github.com/asterisk/asterisk/security/advisories/GHSA-4pgv-j3mr-3rcp
- https://github.com/asterisk/asterisk/commit/4373f8174bf71c467fc9db96036126d30425b9e8
- https://github.com/asterisk/asterisk/commit/4b360a61d649a7c12b1021aa554642322ee28c10
- https://github.com/asterisk/asterisk/commit/60c23d8b56b2cf93caceb527e07654b16f388343
- https://github.com/asterisk/asterisk/commit/87399593cda601ae3670bf890bdb32f78e881bf3
- https://github.com/asterisk/asterisk/commit/9cff8e62fbd9e7db87c233de3335047df88877d0
- https://github.com/asterisk/asterisk/commit/dc43c5b32a3a216da4c9e95388fbadaca3e78bc8
- https://github.com/asterisk/asterisk/commit/e6998409f73f49959d0062c695bb9a2f611af5ac
- https://github.com/asterisk/asterisk/releases/tag/20.20.1
- https://github.com/asterisk/asterisk/releases/tag/21.12.3
- https://github.com/asterisk/asterisk/releases/tag/22.10.1
- https://github.com/asterisk/asterisk/releases/tag/23.4.1
- https://github.com/asterisk/asterisk/releases/tag/certified-20.7-cert11
- https://github.com/asterisk/asterisk/releases/tag/certified-22.8-cert3
- https://github.com/asterisk/asterisk/tree/24.0.0-pre1
More asterisk vulnerabilities
- TI-2025-30244 Using malformed From header can forge identity with ";" or NULL in name portion CVSS 3.1HIGH 7.7
- TI-2023-27195 Asterisk susceptible to Denial of Service via DTLS Hello packets during call initiation CVSS 3.1HIGH 7.5
- TI-2024-28351 Asterisk allows `Write=originate` as sufficient permissions for code execution / `System()` dialplan CVSS 3.1HIGH 8.8
- TI-2025-00959 Asterisk Unsafe Shell Sourcing in safe_asterisk Leads to Local Privilege Escalation CVSS 4.0HIGH 7.0
- TI-2025-34699 Asterisk remotely exploitable leak of RTP UDP ports and internal resources CVSS 3.1MEDIUM 6.5
- TI-2025-31747 Asterisk is Vulnerable to Remote DoS and possible RCE Attacks During Memory Allocation CVSS 3.1MEDIUM 6.5
Sources
- CVE-2026-57196 · CVE Program
- CVE-2026-57196 · NVD
- FIRST EPSS
- CVE-2026-57196 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences