CVE-2007-3765 in Asterisk
Summary
by MITRE
The STUN implementation in Asterisk 1.4.x before 1.4.8, AsteriskNOW before beta7, Appliance Developer Kit before 0.5.0, and s800i before 1.0.2 allows remote attackers to cause a denial of service (crash) via a crafted STUN length attribute in a STUN packet sent on an RTP port.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/24/2017
The vulnerability described in CVE-2007-3765 represents a critical denial of service flaw within the Session Traversal Utilities for NAT (STUN) implementation of several versions of the Asterisk telephony platform. This vulnerability affects Asterisk 1.4.x versions prior to 1.4.8, AsteriskNOW before beta7, Appliance Developer Kit before 0.5.0, and s800i before 1.0.2, making it a widespread issue across multiple Asterisk-related products. The flaw specifically manifests when the system processes a crafted STUN length attribute within a STUN packet transmitted over RTP ports, leading to system crashes and complete service disruption.
The technical nature of this vulnerability stems from inadequate input validation within the STUN packet processing mechanism. When a remote attacker crafts a malicious STUN packet with an improperly formatted length attribute, the Asterisk system fails to properly handle this malformed data during packet parsing. This parsing failure results in memory corruption or buffer overflow conditions that ultimately cause the Asterisk process to terminate unexpectedly. The vulnerability operates at the network protocol level, specifically targeting the STUN protocol implementation that Asterisk uses for NAT traversal and media session establishment. The attack vector requires only that an attacker send a specially crafted STUN packet to any RTP port where Asterisk is listening, making it particularly dangerous as it can be executed remotely without authentication or prior access to the system.
The operational impact of this vulnerability extends beyond simple service disruption to encompass broader system reliability and availability concerns. When exploited successfully, the vulnerability causes complete system crashes that can take the entire telephony infrastructure offline, affecting voice communications, conference calls, and any other services relying on the affected Asterisk installations. Organizations using these vulnerable versions face significant risk of service interruptions that can last from minutes to hours depending on system recovery procedures and manual intervention requirements. The vulnerability particularly impacts businesses and service providers that depend on Asterisk for their communication infrastructure, potentially causing financial losses due to downtime and customer service disruptions.
Mitigation strategies for this vulnerability primarily focus on immediate software updates and patches provided by the Asterisk development team. Organizations should upgrade to Asterisk 1.4.8 or later versions where this vulnerability has been addressed through proper input validation and error handling mechanisms. Network-level mitigations can include implementing firewalls or intrusion prevention systems to filter STUN traffic or restrict access to RTP ports from untrusted networks. Additionally, administrators should consider disabling STUN functionality if it is not required for their specific deployment, as this removes the attack surface entirely. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and maps to ATT&CK technique T1499.004 for network denial of service attacks. Regular security monitoring and vulnerability assessment procedures should be implemented to identify and remediate similar issues in other network services and telephony systems that may be vulnerable to similar input validation flaws.