A heap-based buffer overflow vulnerability was found in Samba within the GSSAPI unwrapdes() and unwrapdes3() routines of Heimdal. The DES and Triple-DES decryption routines in the Heimdal GSSAPI library allow a length-limited write buffer overflow on malloc() allocated memory when presented with a maliciously small packet. This flaw allows a remote user to send specially crafted malicious data to the application, possibly resulting in a denial of service (DoS) attack.