Skip to content

Missing Token Replay Detection in Saml2 Authentication services for ASP.NET

High severity GitHub Reviewed Published Mar 24, 2020 in Sustainsys/Saml2 • Updated Feb 1, 2023

Package

nuget Sustainsys.Saml2 (NuGet)

Affected versions

>= 2.0.0, < 2.5.0

Patched versions

2.5.0

Description

Impact

Token Replay Detection is an important defence in depth measure for Single Sign On solutions. In all previous 2.X versions, the Token Replay Detection is not properly implemented.

Note that version 1.0.1 is not affected. It has a correct Token Replay Implementation and is safe to use.

Patches

The 2.5.0 version is patched.

Workarounds

There are no workarounds with existing versions. Fixing the issue requires code updates.

References

https://en.wikipedia.org/wiki/Replay_attack

For more information

If you have any questions or comments about this advisory:

References

@AndersAbel AndersAbel published to Sustainsys/Saml2 Mar 24, 2020
Reviewed Mar 25, 2020
Published by the National Vulnerability Database Mar 25, 2020
Published to the GitHub Advisory Database Mar 25, 2020
Last updated Feb 1, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N

EPSS score

0.100%
(43rd percentile)

Weaknesses

CVE ID

CVE-2020-5261

GHSA ID

GHSA-g6j2-ch25-5mmv

Source code

No known source code
Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.