CVE-2015-1379 in Socat
Summary
by MITRE
The signal handler implementations in socat before 1.7.3.0 and 2.0.0-b8 allow remote attackers to cause a denial of service (process freeze or crash).
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Analysis
by VulDB Data Team • 02/27/2025
The vulnerability identified as CVE-2015-1379 affects the socat network utility, a widely used tool for creating bidirectional byte streams and transferring data between network sockets and other file descriptors. This issue resides in the signal handler implementations within socat versions prior to 1.7.3.0 and 2.0.0-b8, creating a critical weakness that remote attackers can exploit to induce denial of service conditions. The flaw manifests when the application processes signals in a manner that leads to process freezing or crashes, effectively rendering the service unavailable to legitimate users.
The technical root cause of this vulnerability stems from improper handling of asynchronous signal delivery within the socat application. When signals are received during critical execution phases, particularly those involving network operations or file descriptor management, the signal handlers may not properly restore the application state or may enter deadlock conditions. This behavior aligns with CWE-475, which describes improper handling of a situation where a program has an undefined state due to an unexpected signal, and also relates to CWE-674, which addresses uncontrolled recursion in signal handlers. The vulnerability demonstrates a classic race condition scenario where signal processing interferes with normal program execution flow, leading to system instability.
From an operational perspective, this vulnerability poses significant risks to systems relying on socat for network connectivity, particularly in environments where the tool serves as a critical component for data transfer or network bridging. Remote attackers can exploit this weakness by sending carefully crafted signals to the socat process, causing it to freeze or crash and thereby disrupting network services. The impact extends beyond simple service interruption, as socat is frequently used in automated systems, network debugging tools, and as part of larger network infrastructure components. This makes the vulnerability particularly dangerous in enterprise environments where continuous network availability is critical for business operations.
The exploitation of this vulnerability follows patterns consistent with ATT&CK technique T1499.004, which involves network disruption through the use of denial of service attacks. Attackers can leverage this weakness to target systems running vulnerable versions of socat, potentially affecting services such as network tunnels, proxy connections, or any application that depends on socat for network communication. The vulnerability's remote nature means that attackers do not require local access to the system, making it a particularly attractive target for network-based attacks. Organizations should consider implementing network segmentation and monitoring for unusual signal activity patterns as part of their defensive strategies against this type of attack vector.
Mitigation strategies for CVE-2015-1379 primarily involve upgrading to socat versions 1.7.3.0 or 2.0.0-b8, where the signal handler implementations have been corrected to prevent the problematic behavior. System administrators should also implement proper process monitoring and alerting mechanisms to detect when socat processes become unresponsive or crash. Additionally, network firewalls and access control lists should be configured to limit exposure of socat services to trusted networks only, reducing the attack surface. The vulnerability highlights the importance of proper signal handling in long-running network services and underscores the need for thorough testing of signal processing code in security-critical applications. Organizations should also consider implementing application-level firewalls or proxy configurations that can detect and block malicious signal patterns before they reach the vulnerable socat processes.