CVE-2020-5268Network attack vector

Login session creation via ignored subject confirmation

Published Apr 21, 2020 · Updated Aug 4, 2024

Improper authentication in Sustainsys.Saml2 before 1.0.2 and 2.0.0 through 2.6.0 allows remote authenticated users to create login sessions. Incoming SAML assertion validation treats every subject-confirmation method as bearer and does not require the proof specified by non-bearer methods. Exploitation requires access to a token using another method, such as holder-of-key, and the resulting session assumes the token's subject.

CVSS severity6.5
Medium
EPSS probability1.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Sustainsys.Saml2 before 1.0.2 and 2.0.0 through 2.6.0 allows remote authenticated users to create login sessions. Incoming SAML assertion validation treats every subject-confirmation method as bearer and does not require the proof specified by non-bearer methods. Exploitation requires access to a token using another method, such as holder-of-key, and the resulting session assumes the token's subject.

The record

CVE
CVE-2020-5268
Published
Apr 21, 2020
Updated
Aug 4, 2024
Vendor
Sustainsys
Product
Sustainsys.Saml2
Classifications
CWE-287, CWE-303
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 21, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.0.2
  2. Affected versionversion=>= 2.0.0, <= 2.6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Sustainsys · Sustainsys.Saml2version=< 1.0.2; version=>= 2.0.0, <= 2.6.0

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:L/A:N
7.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
4.9NIST NVDAV:N/AC:M/Au:S/C:P/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
CWE-303Incorrect Implementation of Authentication Algorithm

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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