CVE-2021-29136

Name: CVE-2021-29136
Creator: NVD / NIST
Published: 2021-04-06T16:15:16.52+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.34%

Last modified Jun 17, 2026

CVE-2021-29136 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. Open Container Initiative umoci before 0.4.7 allows attackers to overwrite arbitrary host paths via a crafted image that causes symlink traversal when "umoci unpack" or "umoci raw unpack" is used.. EPSS estimates a 0.34% chance of exploitation in the next 30 days.

Description

Open Container Initiative umoci before 0.4.7 allows attackers to overwrite arbitrary host paths via a crafted image that causes symlink traversal when "umoci unpack" or "umoci raw unpack" is used.

Metrics

CVSS 3.1

5.5/10

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

EPSS Probability

0.34%

26.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-20

Affected Software

Vendor	Product	Versions
Linuxfoundation	Umoci	< 0.4.7
Sylabs	Singularity	< 3.7.3

References

http://www.openwall.com/lists/oss-security/2021/04/06/2Mailing List, Patch, Third Party Advisory
https://github.com/opencontainers/umoci/commit/d9efc31daf2206f7d3fdb839863cf7a576a2eb57Patch, Third Party Advisory
https://github.com/opencontainers/umoci/security/advisories/GHSA-9m95-8hx6-7p9vThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/04/06/2Mailing List, Patch, Third Party Advisory
https://github.com/opencontainers/umoci/commit/d9efc31daf2206f7d3fdb839863cf7a576a2eb57Patch, Third Party Advisory
https://github.com/opencontainers/umoci/security/advisories/GHSA-9m95-8hx6-7p9vThird Party Advisory

Timeline

Published: Apr 6, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-29136?

Open Container Initiative umoci before 0.4.7 allows attackers to overwrite arbitrary host paths via a crafted image that causes symlink traversal when "umoci unpack" or "umoci raw unpack" is used.

How severe is CVE-2021-29136?

CVE-2021-29136 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.34% probability of exploitation in the next 30 days.

How do I fix CVE-2021-29136?

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-2021-29136?

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

Scan your code now

Source: NVD / NIST