Asterisk ARI read-only users can write files through FILE()
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
Asterisk versions before 20.20.1, from 21.0.0-pre1 before 21.12.3, from 22.0.0-pre1 before 22.10.1, and from 23.0.0-pre1 before 23.4.1 are affected, as are Certified Asterisk versions before 20.7-cert11 and from 22.8-cert1-pre1 before 22.8-cert3. The setChannelVar operation in the ARI lets an authenticated attacker run write dialplan functions such as FILE() even when live_dangerously is set to no (CWE-267). The attacker needs valid read-only ARI credentials, and the HTTP server must be enabled and 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 authenticated Asterisk REST Interface (ARI) attacker with read-only privileges may use `setChannelVar` to execute write dialplan functions, including `FILE()` writes, even when `live_dangerously` in `asterisk.conf` is set to no. The Asterisk HTTP web server must be enabled and reachable, and the attacker must already have valid `read-only ARI credentials`. HTTP is disabled by default and binds only to 127.0.0.1 by default even when enabled. 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
- Total
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 upgrade Certified Asterisk to 20.7-cert11 or 22.8-cert3.
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
- 2026-10-27 Threatist record created from CVE-2026-57202
- 2026-10-28 CISA SSVC decision points changed
- 2026-10-28 Priority changed: MEDIUM → LOW
- 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-vrfp-mg3q-3959
- https://github.com/asterisk/asterisk/commit/8f8ccaf70a80e518147b0c35c0c252de4735446f
- https://github.com/asterisk/asterisk/commit/92a5dd1003b737ae1cd2df4e60b73beb8d5e42bb
- https://github.com/asterisk/asterisk/commit/ba04e7f1f98887c3c6e0dc4ddce663021f7e948a
- https://github.com/asterisk/asterisk/commit/bf9354267557ef6d6b75f5304faa243f595a5a66
- https://github.com/asterisk/asterisk/commit/caa4d50d9c3bf04fc979b5b2cdc5dc425772d845
- https://github.com/asterisk/asterisk/commit/d47b0b6e5a384746db194f751b53d559aba8dba9
- https://github.com/asterisk/asterisk/commit/d8614505b27688dec3a1d14554f52fda94712928
- 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-2026-57202 · CVE Program
- CVE-2026-57202 · NVD
- FIRST EPSS
- CVE-2026-57202 · 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