Several issues have been discovered in mumble, a low latency VoIP client. The Common Vulnerabilities and Exposures project identifies the following issues:
It was discovered that a malformed Opus voice packet sent to a Mumble client could trigger a NULL pointer dereference or an out-of-bounds array access. A malicious remote attacker could exploit this flaw to mount a denial of service attack against a mumble client by causing the application to crash.
It was discovered that a malformed Opus voice packet sent to a Mumble client could trigger a heap-based buffer overflow. A malicious remote attacker could use this flaw to cause a client crash (denial of service) or potentially use it to execute arbitrary code.
The oldstable distribution (squeeze) is not affected by these problems.
For the stable distribution (wheezy), these problems have been fixed in version 1.2.3-349-g315b5f5-2.2+deb7u1.
For the unstable distribution (sid), these problems will be fixed soon.
We recommend that you upgrade your mumble packages.