CVE-2013-2222 in ZRTPCPP
Summary
by MITRE
Multiple stack-based buffer overflows in GNU ZRTPCPP before 3.2.0 allow remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted ZRTP Hello packet to the (1) ZRtp::findBestSASType, (2) ZRtp::findBestAuthLen, (3) ZRtp::findBestCipher, (4) ZRtp::findBestHash, or (5) ZRtp::findBestPubKey functions.
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Analysis
by VulDB Data Team • 01/08/2022
The vulnerability identified as CVE-2013-2222 represents a critical stack-based buffer overflow in the GNU ZRTPCPP library version 3.1.0 and earlier, which serves as a core component for implementing ZRTP security protocols in VoIP communications. This flaw affects the ZRtp class methods responsible for determining the best security parameters during ZRTP handshake negotiations, specifically targeting functions that process authentication lengths, cipher algorithms, hash functions, public key types, and SAS (Short Authentication String) types. The vulnerability arises from insufficient input validation when processing crafted ZRTP Hello packets that contain maliciously formatted data structures, creating opportunities for attackers to manipulate memory layout through stack corruption.
The technical exploitation of this vulnerability occurs through remote code execution via specially crafted ZRTP Hello packets that are sent to systems using vulnerable versions of the GNU ZRTPCPP library. When the affected functions attempt to parse and process these malformed packets, they fail to properly validate buffer boundaries, allowing attackers to overwrite adjacent stack memory locations with controlled data. The stack-based nature of the overflow means that return addresses, saved registers, and local variables can be overwritten, potentially leading to arbitrary code execution or system crashes. This vulnerability directly maps to CWE-121 Stack-based Buffer Overflow, which is classified under the Common Weakness Enumeration framework as a fundamental memory safety issue.
The operational impact of CVE-2013-2222 extends beyond simple denial of service scenarios, as it provides attackers with potential paths for privilege escalation and persistent system compromise within VoIP environments. Systems utilizing GNU ZRTPCPP for secure voice communications, including SIP-based telephony systems, instant messaging applications, and enterprise communication platforms, become vulnerable to remote exploitation. The attack surface is particularly concerning in enterprise environments where ZRTP is used for securing sensitive communications, as successful exploitation could lead to complete system compromise or data exfiltration. This vulnerability aligns with ATT&CK technique T1203 Exploitation for Client Execution, which describes how attackers leverage software vulnerabilities to execute malicious code on target systems.
Mitigation strategies for CVE-2013-2222 require immediate implementation of version updates to GNU ZRTPCPP 3.2.0 or later, which contain proper input validation and buffer boundary checking mechanisms. Organizations should also implement network segmentation and monitoring to detect anomalous ZRTP Hello packet traffic patterns that may indicate exploitation attempts. Additional defensive measures include deploying intrusion detection systems with signature-based detection for known malicious ZRTP packet structures, implementing network access controls to restrict unauthorized ZRTP traffic, and conducting comprehensive vulnerability assessments of all systems using affected libraries. Security teams should also consider implementing application-level firewalls and packet filtering rules that can identify and block malformed ZRTP Hello packets, while maintaining detailed logging of ZRTP handshake activities for forensic analysis purposes.