A flaw was found in gss-ntlmssp. A memory leak occurs in the NTLM target-info parser when a crafted NTLM CHALLENGE message contains duplicated string-valued AVPAIR entries. The parser allocates memory for each string value but does not free the previous allocation when the same AVPAIR type appears more than once, leaking the earlier allocation. A malicious or man-in-the-middle server can exploit this to cause gradual memory exhaustion on the client during NTLM authentication, leading to a denial of service.

GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, multiple out-of-bounds reads when decoding NTLM fields can trigger a denial of service. A 32-bit integer overflow condition can lead to incorrect checks of consistency of length of internal buffers. Although most applications will error out before accepting a singe input buffer of 4GB in length this could theoretically happen. This vulnerability can be triggered via the main gssacceptseccontext entry point if the application allows tokens greater than 4GB in length. This can lead to a large, up to 65KB, out-of-bounds read which could cause a denial-of-service if it reads from unmapped memory. Version 1.2.0 contains a patch for the out-of-bounds reads.

GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, memory corruption can be triggered when decoding UTF16 strings. The variable outlen was not initialized and could cause writing a zero to an arbitrary place in memory if ntlmstrconvert() were to fail, which would leave outlen uninitialized. This can lead to a denial of service if the write hits unmapped memory or randomly corrupts a byte in the application memory space. This vulnerability can trigger an out-of-bounds write, leading to memory corruption. This vulnerability can be triggered via the main gssacceptseccontext entry point. This issue is fixed in version 1.2.0.

GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, an incorrect free when decoding target information can trigger a denial of service. The error condition incorrectly assumes the cb and sh buffers contain a copy of the data that needs to be freed. However, that is not the case. This vulnerability can be triggered via the main gssacceptseccontext entry point. This will likely trigger an assertion failure in free, causing a denial-of-service. This issue is fixed in version 1.2.0.

GSS-NTLMSSP is a mechglue plugin for the GSSAPI library that implements NTLM authentication. Prior to version 1.2.0, a memory leak can be triggered when parsing usernames which can trigger a denial-of-service. The domain portion of a username may be overridden causing an allocated memory area the size of the domain name to be leaked. An attacker can leak memory via the main gssacceptseccontext entry point, potentially causing a denial-of-service. This issue is fixed in version 1.2.0.

GSS-NTLMSSP, a mechglue plugin for the GSSAPI library that implements NTLM authentication, has an out-of-bounds read when decoding target information prior to version 1.2.0. The length of the avpair is not checked properly for two of the elements which can trigger an out-of-bound read. The out-of-bounds read can be triggered via the main gssacceptseccontext entry point and could cause a denial-of-service if the memory is unmapped. The issue is fixed in version 1.2.0.