CVE Vulnerabilities

CVE-2020-5261

Authentication Bypass by Capture-replay

Published: Mar 25, 2020 | Modified: Mar 24, 2021
CVSS 3.x
6.8
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS 2.x
4.9 MEDIUM
AV:N/AC:M/Au:S/C:P/I:P/A:N
RedHat/V2
RedHat/V3
Ubuntu

Saml2 Authentication services for ASP.NET (NuGet package Sustainsys.Saml2) greater than 2.0.0, and less than version 2.5.0 has a faulty implementation of Token Replay Detection. Token Replay Detection is an important defence in depth measure for Single Sign On solutions. The 2.5.0 version is patched. Note that version 1.0.1 is not affected. It has a correct Token Replay Implementation and is safe to use. Saml2 Authentication services for ASP.NET (NuGet package Sustainsys.Saml2) greater than 2.0.0, and less than version 2.5.0 have a faulty implementation of Token Replay Detection. Token Replay Detection is an important defense measure for Single Sign On solutions. The 2.5.0 version is patched. Note that version 1.0.1 and prior versions are not affected. These versions have a correct Token Replay Implementation and are safe to use.

Weakness

A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).

Affected Software

Name Vendor Start Version End Version
Saml2 Sustainsys 2.0.0 (including) 2.5.0 (excluding)

Potential Mitigations

References