PT-2026-51073 · Nuget · Corewcf.Unixdomainsocket
Published
2026-06-19
·
Updated
2026-06-19
·
CVE-2026-54776
CVSS v3.1
4.4
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
Impact
A CoreWCF service hosted on Unix Domain Sockets with the PosixIdentity client credential type (UnixDomainSocketBinding with Security.Mode = TransportCredentialOnly and Security.Transport.ClientCredentialType = PosixIdentity) does not require the client to perform the application/unixposix stream upgrade before dispatching messages.
Patches
Fixed in CoreWCF v1.8.1 and v1.9.1
Workarounds
Restrict filesystem access to the UDS socket file using owner/group/mode (e.g. chmod 0660 plus a dedicated group) so that only the POSIX users who are already authorized to invoke the service can connect at all. This makes the missing-upgrade behaviour equivalent to the operating system’s filesystem permissions instead of relying on framing-layer identity checks.
Avoid relying on ServiceSecurityContext.PrimaryIdentity for authorization decisions, or back it up with an authentication-required authorization policy that rejects anonymous principals.
Fix
Missing Authentication
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Weakness Enumeration
Related Identifiers
Affected Products
Corewcf.Unixdomainsocket