CVE-2021-21474Network attack vector

User impersonation via collision-altered MD5 SAML assertions

Published Feb 9, 2021 · Updated Aug 3, 2024

Improper authentication in SAP HANA Database 1.0 and 2.0 allows remote authenticated users to impersonate users via a SAML assertion. The SAML verifier accepts MD5-digested assertion content, allowing a collision-altered assertion to retain a valid digital signature. Exploitation requires an MD5-digest-signed assertion issued for the target instance; successful impersonation permits database reads under the mapped user’s authorization.

CVSS severity6.5
Medium
EPSS probability0.70%
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 SAP HANA Database 1.0 and 2.0 allows remote authenticated users to impersonate users via a SAML assertion. The SAML verifier accepts MD5-digested assertion content, allowing a collision-altered assertion to retain a valid digital signature. Exploitation requires an MD5-digest-signed assertion issued for the target instance; successful impersonation permits database reads under the mapped user’s authorization.

The record

CVE
CVE-2021-21474
Published
Feb 9, 2021
Updated
Aug 3, 2024
Vendor
SAP SE
Product
SAP HANA
Classifications
CWE-326, T1606.002
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 9, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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. Affected versionversion=< 2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

SAP SE · SAP HANAversion=< 1.0; version=< 2.0

Published CVSS scores

5.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:N
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-326Inadequate Encryption Strength
T1606.002Forge Web Credentials: SAML Tokens

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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