Asterisk – Bypass ACL Restriction on Different Asterisk Products

Advisory ID


Vulnerability Information



Is possible to bypass the whitelist and blacklist that can be created on various modules in Asterisk via ACL options. There is a bug on the ACL code where an attacker can bypass them using a packet with a source IP that does not match the address family as the first ACL entry.

The vulnerability affects all VoIP driver channels, DUNDi and Asterisk Manager Interface (AMI).

Technical Information



Many modules in Asterisk that service incoming IP traffic have ACL options (“permit” and “deny”) that can be used to whitelist or blacklist address ranges. A bug has been discovered where the address family of incoming packets is only compared to the IP address family of the first entry in the list of access control rules. If the source IP address for an incoming packet is not of the same address family as the first ACL entry, that packet bypasses all ACL rules. For ACLs whose rules are all of the same address family, there is no issue.


Release Date




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External Resources



Common Vulnerabilities and Exposures (CVE)

Asterisk Project Security Advisory