CVE-2021-29221

Name: CVE-2021-29221
Creator: NVD / NIST
Published: 2021-04-09T14:15:12.91+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7/10EPSS 0.58%

Last modified Jun 17, 2026

CVE-2021-29221 is a high-severity vulnerability rated 7/10 on the CVSS scale. A local privilege escalation vulnerability was discovered in Erlang/OTP prior to version 23.2.3. By adding files to an existing installation's directory, a local attacker could hijack accounts of other users running Erlang programs or possibly coerce a service running with "erlsrv.exe" to execute arbitrary code as Local System. EPSS estimates a 0.58% chance of exploitation in the next 30 days.

Description

A local privilege escalation vulnerability was discovered in Erlang/OTP prior to version 23.2.3. By adding files to an existing installation's directory, a local attacker could hijack accounts of other users running Erlang programs or possibly coerce a service running with "erlsrv.exe" to execute arbitrary code as Local System. This can occur only under specific conditions on Windows with unsafe filesystem permissions.

Metrics

CVSS 3.1

7/10

CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

0.58%

43.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-426

Affected Software

Vendor	Product	Versions
Erlang	Erlang\/Otp	< 23.2.3

References

https://deepsurface.com/deepsurface-security-advisory-local-privilege-escalation-in-erlang-on-windows-cve-2021-29221/Exploit, Third Party Advisory
https://github.com/erlang/otp/releases/tag/OTP-23.2.3Third Party Advisory
https://deepsurface.com/deepsurface-security-advisory-local-privilege-escalation-in-erlang-on-windows-cve-2021-29221/Exploit, Third Party Advisory
https://github.com/erlang/otp/releases/tag/OTP-23.2.3Third Party Advisory

Timeline

Published: Apr 9, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-29221?

How severe is CVE-2021-29221?

CVE-2021-29221 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 0.58% probability of exploitation in the next 30 days.

How do I fix CVE-2021-29221?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-29221?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST