CVE-2021-29221: A local privilege escalation vulnerability was discovered in Erlang/OTP prior to version 23.2.3

Q: How do I fix CVE-2021-29221?

erlang\/otp: upgrade to 23.2.3. Exact commands for each OS are on this page.

Q: Is CVE-2021-29221 being exploited?

CVE-2021-29221 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-29221 affect?

CVE-2021-29221 affects erlang\/otp. Severity is high (CVSS 7.0). 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 possi

Q: How urgent is CVE-2021-29221?

Priority 41/100. High severity; Public exploit reference

This month

HIGH 7.0UPGRADE

CVE-2021-29221 is a high-severity flaw (CVSS 7.0) affecting erlang\/otp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	7.0 (High)
Attack vector	Local
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.6% (top 52%)
CISA exploited list	No
Weakness	CWE-426
Published	2021-04-09
Last modified	2026-06-17

Publisher (CNA): DeepSurface Security, Inc. · Vendor: erlang

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-04-09 14:15 UTCPublished CVE record published
2026-06-17 03:47 UTCUpdated Record last modified

erlang erlang\/otp UPGRADE

Affected: < 23.2.3

Fixed in: 23.2.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy erlangotp || rpm -q erlangotp || erlangotp --version

2. UPGRADE to 23.2.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade erlangotp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade erlangotp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-29221?

erlang\/otp: upgrade to 23.2.3. Exact commands for each OS are on this page.

Is CVE-2021-29221 being exploited?

CVE-2021-29221 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-29221 affect?

CVE-2021-29221 affects erlang\/otp. Severity is high (CVSS 7.0). 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 possi

How urgent is CVE-2021-29221?

Priority 41/100. High severity; Public exploit reference

Software pages

Windows vulnerabilities

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References

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