SAP takes the security of its vast product portfolio very seriously and thus releases security fixes for
vulnerabilities reported by external researchers and their customers every second Tuesday of the month.
SAP Note 2992154
was released on
09.02.2021 and deals with
"[CVE-2021-21474] SAML Assertion Signature MD5 Digest Algorithm Vulnerability in SAP HANA Database" within SAP HANA Platform.
We advice you to follow the instructions, to resolve
weak security defaults
medium potential for exploitation
in component HAN-DB-SEC.
According to SAP Security Advisory team a workaround exists. It is advisable to implement the correction as part of maintenance.
Risk specificationSAP HANA Database, versions - 1.0, 2.0, accepts SAML tokens with MD5 digest, an attacker who manages to obtain an MD5-digest signed SAML Assertion issued for an SAP HANA instance might be able to tamper with it and alter it in a way that the digest continues to be the same and without invalidating the digital signature, this allows them to impersonate a user in HANA database and be able to read the contents in the database.
MD5 digest support in SAML assertions has been removed from SAP HANA 2. With SAP HANA 1.0 revision 122.34, a new parameter has been added to disable MD5 in the configuration. Alternativly, the consulting team has proposed the following: "Disable MD5 for HANA 1.00 by using SQL command, please execute: ALTER SYSTEM ALTER CONFIGURATION ('global.ini', 'SYSTEM') SET ('authentication', 'saml_signature_hash_types') = 'sha1,sha256' WITH RECONFIGURE';". The suggestion may be considered, as a workaround or compensating mitigation. We recommend installing/applying the correction wherever possible and as soon as possible. Base your decision on whether or not to apply the patch on your companies and systems risk perspective and consider the provided CVSS 4.1 score.