CVE-2026-57193 asterisk CVE debrief

Who should care

Defenders responsible for Asterisk installations, particularly those using the res_config_ldap module, should assess exposure and apply patches or mitigations as needed. This includes verifying if the module is loaded and configured, reviewing system logs for suspicious activity, and ensuring that appropriate compensating controls are in place. Additionally, security teams and vulnerability management teams should prioritize verifying the vulnerability's

Why it matters

Defenders should prioritize verifying if the res_config_ldap module is loaded and configured, and apply patches or mitigations as needed to prevent potential LDAP filter injection attacks.

• Potential information disclosure through LDAP queries
• Possible unauthorized access to sensitive information

Technical summary

The LDAP realtime driver res_config_ldap in Asterisk may permit LDAP filter injection through a SIP username, allowing an unauthenticated attacker to make arbitrary LDAP queries and disclose information. The vulnerability arises from the module's improper handling of user input, specifically SIP usernames, which can be manipulated to inject malicious LDAP filters. This issue affects Asterisk versions prior to 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk versions prior to 20.7-cert11, 22.8-cert3. The res_config_ldap module must be loaded and configured to access an LDAP server

Defensive priority

Defenders should prioritize verifying if the res_config_ldap module is loaded and configured, and apply patches or mitigations as needed.

Recommended defensive actions

• Verify if the res_config_ldap module is loaded and configured
• Apply patches or mitigations as needed
• Monitor for suspicious LDAP queries
• Review compensating controls for exposed systems
• Check relevant monitoring, detection, and logs for exposed assets
• Track exceptions and retest remediated assets
• Confirm whether affected product deployments exist in managed environments

Evidence notes

The CVE record and NVD vulnerability detail page provide information on the vulnerability, but do not provide evidence of exploitation or specific affected versions beyond Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3. The res_config_ldap module's configuration and loading status should be verified by defenders. There is no indication of in-the-wild exploitation, but defenders should assess exposure and apply patches or mitigations as needed. The vulnerability's impact is potentially severe,

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.