free5GC is an open-source implementation of the 5G core network. Prior to 1.4.5, the AUSF component performs cryptographic authentication comparisons in internal/sbi/processor/ue_authentication.go with ordinary equality helpers. Auth5gAkaComfirmRequestProcedure compares RES* and XRES* with strings.EqualFold and logs the expected XRES* value at INFO level before comparison. EapAuthComfirmRequestProcedure compares AT_MAC and XMAC with bytes.Equal and evaluates XRES == RES with ordinary string equality. These comparisons can return at mismatch-dependent times, although testing did not demonstrate a practical remote timing oracle because of HTTP/SBI timing noise. The INFO log exposes authentication material to operators, log collectors, sidecars, or processes able to read AUSF logs. This issue is fixed in version 1.4.5.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-fp46-6vfw-gc9c | free5GC AUSF uses non-constant-time authentication comparisons and logs XRES* in 5G-AKA |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sat, 29 Aug 2026 00:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Free5gc
Free5gc free5gc |
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| Vendors & Products |
Free5gc
Free5gc free5gc |
Fri, 28 Aug 2026 22:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | free5GC is an open-source implementation of the 5G core network. Prior to 1.4.5, the AUSF component performs cryptographic authentication comparisons in internal/sbi/processor/ue_authentication.go with ordinary equality helpers. Auth5gAkaComfirmRequestProcedure compares RES* and XRES* with strings.EqualFold and logs the expected XRES* value at INFO level before comparison. EapAuthComfirmRequestProcedure compares AT_MAC and XMAC with bytes.Equal and evaluates XRES == RES with ordinary string equality. These comparisons can return at mismatch-dependent times, although testing did not demonstrate a practical remote timing oracle because of HTTP/SBI timing noise. The INFO log exposes authentication material to operators, log collectors, sidecars, or processes able to read AUSF logs. This issue is fixed in version 1.4.5. | |
| Title | free5GC AUSF uses non-constant-time authentication comparisons and logs XRES* in 5G-AKA | |
| Weaknesses | CWE-208 CWE-385 CWE-532 |
|
| References |
| |
| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-08-28T22:25:06.814Z
Reserved: 2026-06-17T14:40:28.380Z
Link: CVE-2026-55785
No data.
Status : Received
Published: 2026-08-28T23:17:07.697
Modified: 2026-08-28T23:17:07.697
Link: CVE-2026-55785
No data.
OpenCVE Enrichment
Updated: 2026-08-29T00:15:06Z
Github GHSA