CVE-2014-3952

Vulnerability

A kernel memory disclosure vulnerability exists in FreeBSD's control message API, where the buffer between the control message header and data is not fully initialized before being copied to userland [1]. This affects FreeBSD 8.4 before p14, 9.1 before p17, 9.2 before p10, and 10.0 before p7 [1]. The issue is triggered when a local user uses the sendmsg(2) or recvmsg(2) system calls to construct or receive ancillary data objects [1].

Exploitation

An attacker must have local access to the system and be able to invoke the affected system calls. No special privileges are required beyond a standard user account. By crafting or receiving control messages with uninitialized padding, the attacker can cause the kernel to copy uninitialized kernel memory into user space [1]. The advisory notes the vectors are unspecified but involve the control message API [1].

Impact

Successful exploitation results in the disclosure of sensitive kernel memory contents to the local user. This can include cryptographic keys, passwords, or other confidential data resident in kernel memory, leading to a breach of confidentiality [1]. The attacker does not gain code execution or privilege escalation directly from this flaw.

Mitigation

FreeBSD has released patches for all supported branches: 8.4-RELEASE-p14, 9.1-RELEASE-p17, 9.2-RELEASE-p10, and 10.0-RELEASE-p7 [1]. Users should update to the patched versions or apply the corresponding source patches. No workaround is available; updating is the only mitigation [1].