What is CVE-2021-21478?

CVE-2021-21478 is a medium-severity vulnerability in SAP Web Dynpro Abap, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2021-02-09.

How severe is CVE-2021-21478?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Open Redirect in SAP Web Dynpro Abap

CVE-2021-21478

SAP Web Dynpro ABAP allow an attacker to redirect users to a malicious site due to Reverse Tabnabbing vulnerabilities.

Vulnerability class: Open Redirect

Published 2021-02-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.009 (56.6th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

SAP Web Dynpro Abap
SAP Se Netweaver As Abap (Web Dynpro Abap) — versions < SAP_UI 750, < 752, < 753

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

References

wiki.scn.sap.com/wiki/pages/viewpage.action (Vendor Advisory)
launchpad.support.sap.com/ (Permissions Required)

Frequently asked questions

What is CVE-2021-21478?: CVE-2021-21478 is a medium-severity vulnerability in SAP Web Dynpro Abap, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2021-02-09.
How severe is CVE-2021-21478?: Medium severity. CVSS v3 base score is 6.1 out of 10.