Service crash via integer-wrapped NTLM field bounds
Published Feb 14, 2023 · Updated Mar 10, 2025
Out-of-bounds reads in GSS-NTLMSSP before 1.2.0 allow remote attackers to crash an NTLM-authenticating service via oversized tokens. The ntlm_decode_oem_str, ntlm_decode_u16l_str_hdr, and ntlm_decode_field functions add 32-bit offsets and lengths before bounds checks, allowing integer wraparound to approve an out-of-range read. Reachability requires an application to pass a token larger than 4 GB to gss_accept_sec_context; the resulting read can extend about 65 KB into unmapped memory and terminate the service.
Summary
What happened
Out-of-bounds reads in GSS-NTLMSSP before 1.2.0 allow remote attackers to crash an NTLM-authenticating service via oversized tokens. The ntlm_decode_oem_str, ntlm_decode_u16l_str_hdr, and ntlm_decode_field functions add 32-bit offsets and lengths before bounds checks, allowing integer wraparound to approve an out-of-range read. Reachability requires an application to pass a token larger than 4 GB to gss_accept_sec_context; the resulting read can extend about 65 KB into unmapped memory and terminate the service.
The record
- CVE
- CVE-2023-25563
- Published
- Feb 14, 2023
- Updated
- Mar 10, 2025
- Vendor
- gssapi
- Product
- GSS-NTLMSSP
- Classifications
- CWE-125, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 14, 2023CVE publishedPublication date reported by the CVE source.
- Mar 10, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 1.2.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
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Your stack
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