Description
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.
References10
- github.com/asterisk/asterisk/commit/8f8ccaf70a80e518147b0c35c0c…
- github.com/asterisk/asterisk/commit/92a5dd1003b737ae1cd2df4e60b…
- github.com/asterisk/asterisk/commit/ba04e7f1f98887c3c6e0dc4ddce…
- github.com/asterisk/asterisk/commit/bf9354267557ef6d6b75f5304fa…
- github.com/asterisk/asterisk/commit/caa4d50d9c3bf04fc979b5b2cdc…
- github.com/asterisk/asterisk/commit/d47b0b6e5a384746db194f751b5…
- github.com/asterisk/asterisk/commit/d8614505b27688dec3a1d14554f…
- github.com/asterisk/asterisk/releases/tag/20.20.1
- github.com/asterisk/asterisk/releases/tag/21.12.3
- github.com/asterisk/asterisk/releases/tag/22.10.1
Metrics
- CVSS 3.1
-
8.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - EPSS — exploit probability
- 0% percentile: 38 · as of 4 November 2026
- CWE
- CWE-267CWE-1220
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.