CVE-2021-40391
CVSS v3
9.8
CRITICAL
EPSS Score
3.0 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
An out-of-bounds write vulnerability exists in the drill format T-code tool number functionality of Gerbv 2.7.0, dev (commit b5f1eacd), and the forked version of Gerbv (commit 71493260). A specially-crafted drill file can lead to code execution. An attacker can provide a malicious file to trigger this vulnerability.
Technical details
- Published
- 2021-11-19
Frequently asked questions
What is CVE-2021-40391?
An out-of-bounds write vulnerability exists in the drill format T-code tool number functionality of Gerbv 2.7.0, dev (commit b5f1eacd), and the forked version of Gerbv (commit 71493260). A specially-crafted drill file can lead to code execution. An attacker can provide a malicious file to trigger this vulnerability.
Is CVE-2021-40391 actively exploited?
Active exploitation of CVE-2021-40391 has not been confirmed. Its EPSS score was 3.0% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-40391?
CVE-2021-40391 has a CVSS v3 base score of 9.8 (CRITICAL severity).
Is CVE-2021-40391 affecting your environment?
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