CVE-2026-57193: Asterisk: LDAP Filter Injection in res_config_ldap via SIP Username (Unauthenticated Information Disclosure)

Severity: medium (CVSS 6.9 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-26 · updated 2026-10-31
Weakness: CWE-943

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, the LDAP realtime driver `res_config_ldap` may permit `LDAP filter injection` through a `SIP username`, allowing an unauthenticated attacker to make arbitrary LDAP queries using carefully crafted SIP packets and disclose information. The `res_config_ldap` module must be loaded and configured to access an LDAP server, which is not the default. 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.

Affected products

asterisk: before 20.20.1; from 21.0.0-pre1, < 21.12.3; from 22.0.0-pre1, < 22.10.1; from 23.0.0-pre1, < 23.4.1
asterisk certified-asterisk: before 20.7-cert11; from 22.8-cert1-pre1, < 22.8-cert3

References

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