CVE-2007-2297 in Asterisk
Summary
by MITRE
The SIP channel driver (chan_sip) in Asterisk before 1.2.18 and 1.4.x before 1.4.3 does not properly parse SIP UDP packets that do not contain a valid response code, which allows remote attackers to cause a denial of service (crash).
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Analysis
by VulDB Data Team • 07/14/2021
The vulnerability identified as CVE-2007-2297 affects the SIP channel driver component within Asterisk telephony software systems, specifically impacting versions prior to 1.2.18 and 1.4.x versions before 1.4.3. This issue resides within the core signaling protocol handling mechanism that manages Session Initiation Protocol communications, which forms the backbone of VoIP infrastructure in countless enterprise and telecommunications environments. The flaw represents a critical weakness in the software's packet processing logic that directly impacts the stability and availability of voice communication services.
The technical flaw manifests when the chan_sip driver encounters SIP UDP packets that lack valid response codes during the processing phase. This parsing failure occurs because the software does not adequately validate the structure and content of incoming SIP messages before attempting to process them. When such malformed packets are received, the system's internal state management becomes corrupted, leading to unpredictable behavior and ultimately resulting in a complete system crash. This vulnerability operates at the protocol level, making it particularly dangerous as it can be exploited through standard network traffic without requiring authentication or privileged access.
The operational impact of this vulnerability extends far beyond simple service disruption, as it can effectively disable entire telephony systems that rely on Asterisk for voice communication. Organizations utilizing affected versions of Asterisk face potential business interruption ranging from individual call failures to complete system outages that can affect hundreds or thousands of concurrent users. The remote exploitation capability means attackers can trigger these crashes from any network location without physical access to the system, making the vulnerability particularly attractive to malicious actors seeking to disrupt communications services. This type of denial of service attack can have significant financial implications for businesses that depend on reliable voice infrastructure, with potential losses from downtime and recovery costs.
The vulnerability aligns with CWE-129, which addresses improper validation of input data, and demonstrates characteristics consistent with ATT&CK technique T1499.1, involving network denial of service attacks through system crashes. Organizations should implement immediate mitigations including upgrading to patched versions of Asterisk software, implementing network segmentation to limit exposure, and deploying intrusion detection systems to monitor for suspicious SIP traffic patterns. Additionally, configuring proper packet filtering rules and implementing rate limiting on SIP traffic can help reduce the attack surface while maintaining operational functionality. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in telephony infrastructure components and ensure comprehensive protection against similar threats.