CVE-2016-10325 in oSIP
Summary
by MITRE
In libosip2 in GNU oSIP 4.1.0, a malformed SIP message can lead to a heap buffer overflow in the _osip_message_to_str() function defined in osipparser2/osip_message_to_str.c, resulting in a remote DoS.
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Analysis
by VulDB Data Team • 08/30/2020
The vulnerability identified as CVE-2016-10325 represents a critical heap buffer overflow condition within the GNU oSIP library version 4.1.0, specifically affecting the libosip2 component. This flaw exists in the _osip_message_to_str() function located in the osipparser2/osip_message_to_str.c source file, which is responsible for converting SIP (Session Initiation Protocol) message structures into their string representations. The vulnerability stems from inadequate input validation and memory management when processing malformed SIP messages, creating a scenario where an attacker can craft specially constructed SIP packets that trigger the overflow condition.
The technical implementation of this vulnerability involves the improper handling of buffer boundaries during the string conversion process of SIP messages. When the _osip_message_to_str() function encounters malformed input data, it fails to properly bounds-check memory allocations or validate the length of incoming SIP message components. This allows an attacker to provide input data that exceeds the allocated buffer space, causing a heap-based buffer overflow that can overwrite adjacent memory locations. The vulnerability is particularly dangerous because it occurs during the message serialization phase, meaning that any system processing SIP messages through this library becomes susceptible to exploitation.
From an operational perspective, this vulnerability creates a significant remote denial of service risk for systems utilizing GNU oSIP 4.1.0, particularly those serving as SIP servers, proxies, or gateways. Attackers can remotely trigger the buffer overflow by sending maliciously crafted SIP messages to vulnerable systems, potentially causing application crashes, system instability, or complete service interruption. The impact extends beyond simple service disruption as the heap corruption could potentially allow for more sophisticated attacks if the system's memory layout permits exploitation of the overwritten memory regions. The vulnerability affects any implementation relying on the affected library version, making it a widespread concern across various telephony and communication systems.
The vulnerability maps to CWE-121 in the Common Weakness Enumeration catalog, which specifically addresses stack-based buffer overflow conditions, though this implementation affects heap memory management. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving remote code execution through memory corruption and service denial attacks. The attack surface includes SIP-based communication systems such as VoIP servers, PBX systems, SIP proxies, and any network infrastructure components that process SIP traffic. Organizations utilizing GNU oSIP libraries should prioritize patching or upgrading to versions that address this heap buffer overflow condition, implementing network segmentation to limit exposure, and monitoring for suspicious SIP traffic patterns that may indicate exploitation attempts. Additionally, input validation mechanisms should be strengthened to prevent malformed SIP messages from reaching the vulnerable parsing functions, and regular security assessments should be conducted to identify similar memory management issues in other network protocol libraries.