CVE-2023-25563

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 gss_accept_sec_context 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, 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 gss_accept_sec_context 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.

The gssntlmssp is a GSSAPI NTLM mechanism that allows to perform NTLM authentication in GSSAPI programs.

Security Fix(es):

• gssntlmssp: multiple out-of-bounds read when decoding NTLM fields (CVE-2023-25563)
• gssntlmssp: memory corruption when decoding UTF16 strings (CVE-2023-25564)
• gssntlmssp: incorrect free when decoding target information (CVE-2023-25565)
• gssntlmssp: memory leak when parsing usernames (CVE-2023-25566)
• gssntlmssp: out-of-bounds read when decoding target information (CVE-2023-25567)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Multiple out-of-bounds read when decoding NTLM fields. (CVE-2023-25563) Memory corruption when decoding UTF16 strings. (CVE-2023-25564) Incorrect free when decoding target information. (CVE-2023-25565) Memory leak when parsing usernames. (CVE-2023-25566) Out-of-bounds read when decoding target information. (CVE-2023-25567)

This update for gssntlmssp fixes the following issues:

Update to version 1.2.0

• Implement gss_set_cred_option.
• Allow to gss_wrap even if NEGOTIATE_SEAL is not negotiated.
• Move HMAC code to OpenSSL EVP API.
• Fix crash bug when acceptor credentials are NULL.
• Translations update from Fedora Weblate.

Fix security issues:

• CVE-2023-25563 (boo#1208278): multiple out-of-bounds read when decoding NTLM fields.
• CVE-2023-25564 (boo#1208279): memory corruption when decoding UTF16 strings.
• CVE-2023-25565 (boo#1208280): incorrect free when decoding target information.
• CVE-2023-25566 (boo#1208281): memory leak when parsing usernames.
• CVE-2023-25567 (boo#1208282): out-of-bounds read when decoding target information.

Update to version 1.1

• various build fixes and better compatibility when a MIC is requested.

Update to version 1.0

• Fix test_gssapi_rfc5587.
• Actually run tests with make check.
• Add two tests around NTLMSSP_NEGOTIATE_LMKEY.
• Refine LM compatibility level logic.
• Refactor the gssntlm_required_security function.
• Implement reading LM/NT hashes.
• Add test for smpasswd-like user files.
• Return confidentiality status.
• Fix segfault in sign/seal functions.
• Fix dummy signature generation.
• Use UCS16LE instead of UCS-2LE.
• Provide a zero lm key if the password is too long.
• Completely omit CBs AV pairs when no CB provided.
• Change license to the more permissive ISC.
• Do not require cached users with winbind.
• Add ability to pass keyfile via cred store.
• Remove unused parts of Makefile.am.
• Move attribute names to allocated strings.
• Adjust serialization for name attributes.
• Fix crash in acquiring credentials.
• Fix fallback to external_creds interface.
• Introduce parse_user_name() function.
• Add test for parse_user_name.
• Change how we assemble user names in ASC.
• Use thread local storage for winbind context.
• Make per thread winbind context optional.
• Fixed memleak of usr_cred.
• Support get_sids request via name attributes.
• Fixed memory leaks found by valgrind.

• Update to version 0.9

• add support for getting session key.
• Add gss_inquire_attrs_for_mech().
• Return actual data for RFC5587 API.
• Add new Windows version flags.
• Add Key exchange also when wanting integrity only.
• Drop support for GSS_C_MA_NOT_DFLT_MECH.

These are all security issues fixed in the gssntlmssp-1.2.0-1.1 package on the GA media of openSUSE Tumbleweed.

Root has patched CVE-2023-25563 in the rootio-gss-ntlmssp package for Root:Ubuntu:22.04. Multiple fixed versions available.

Phil Turnbull discovered that GSS NTLMSSP may perform out-of-bounds reads when decoding NTLM fields and target information. An attacker could possibly use this issue to cause GSS NTLMSSP to crash, resulting in a denial of service. (CVE-2023-25563, CVE-2023-25567)

Phil Turnbull discovered that GSS NTLMSSP did not properly initialize memory when decoding UTF16 strings. An attacker could possibly use this issue to trigger an out-of-bounds write, resulting in a crash. (CVE-2023-25564)

Phil Turnbull discovered that GSS NTLMSSP did not properly handle memory cleanup. An attacker could possibly use this issue to cause an assertion failure, resulting in a denial of service. (CVE-2023-25565)