CVE-2016-5080

Vulnerability

An integer overflow vulnerability exists in the rtxMemHeapAlloc function in asn1rt_a.lib of the Objective Systems ASN1C compiler for C/C++ before version 7.0.2. When an application compiled with this compiler parses crafted ASN.1 data, the integer overflow leads to a heap-based buffer overflow, potentially allowing arbitrary code execution or denial of service [1][2][3][4].

Exploitation

An unauthenticated remote attacker can exploit this vulnerability by sending a specially crafted ASN.1 encoded message to a service that uses code compiled with the affected ASN1C compiler. The attacker does not need any prior authentication or local access. The message triggers the integer overflow in the memory allocation routine, causing a heap-based buffer overflow [2][3].

Impact

Successful exploitation could allow the attacker to execute arbitrary code on the target system with the privileges of the affected process, or cause a denial of service (system crash or instability). The vulnerability is remotely exploitable and requires no user interaction [2][3][4].

Mitigation

The vulnerability is fixed in ASN1C version 7.0.2. Cisco has released software updates for affected products (Cisco ASR 5000 StarOS and Virtualized Packet Core) [4]. No workarounds are available. Users should update the ASN1C compiler to version 7.0.2 or later, and apply patches from vendors using the compiler [1][2][3][4].