HOME VULNERABILITIESCVE-2021-41110

CRITICAL

CVE-2021-41110

CWE-502Published: October 1, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

cwlviewer is a web application to view and share Common Workflow Language workflows. Versions prior to 1.3.1 contain a Deserialization of Untrusted Data vulnerability. Commit number f6066f09edb70033a2ce80200e9fa9e70a5c29de (dated 2021-09-30) contains a patch. There are no available workarounds aside from installing the patch. The SnakeYaml constructor, by default, allows any data to be parsed. To fix the issue the object needs to be created with a `SafeConstructor` object, as seen in the patch.

Technical Analysis

CVE-2021-41110 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-502): Insecure deserialization vulnerabilities allow attackers to inject malicious objects during deserialization, potentially enabling remote code execution.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected Vendors & Products

commonwl1 product(s)

cwlviewer

Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

Security advisories & exploits

Official NIST entry

CVE Program entry

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/common-workflow-language/cwlviewer/commit/f6066f09edb70033a2ce80200e9fa9e70a5c29de

PATCHhttps://github.com/common-workflow-language/cwlviewer/security/advisories/GHSA-7g7j-f5g3-fqp7

PATCHhttps://github.com/common-workflow-language/cwlviewer/commit/f6066f09edb70033a2ce80200e9fa9e70a5c29de

PATCHhttps://github.com/common-workflow-language/cwlviewer/security/advisories/GHSA-7g7j-f5g3-fqp7

ADVISORYhttps://www.fatalerrors.org/a/analysis-of-the-snakeyaml-deserialization-in-java-security.html

ADVISORYhttps://www.fatalerrors.org/a/analysis-of-the-snakeyaml-deserialization-in-java-security.html

All References (6)

→

https://github.com/common-workflow-language/cwlviewer/commit/f6066f09edb70033a2ce80200e9fa9e70a5c29dePatch · Third Party Advisory

→

https://github.com/common-workflow-language/cwlviewer/security/advisories/GHSA-7g7j-f5g3-fqp7Patch · Third Party Advisory

→

https://www.fatalerrors.org/a/analysis-of-the-snakeyaml-deserialization-in-java-security.htmlExploit · Third Party Advisory

→

https://github.com/common-workflow-language/cwlviewer/commit/f6066f09edb70033a2ce80200e9fa9e70a5c29dePatch · Third Party Advisory

→

https://github.com/common-workflow-language/cwlviewer/security/advisories/GHSA-7g7j-f5g3-fqp7Patch · Third Party Advisory

→

https://www.fatalerrors.org/a/analysis-of-the-snakeyaml-deserialization-in-java-security.htmlExploit · Third Party Advisory

Quick Facts

CVE IDCVE-2021-41110

CVSS Score9.8 / 10

SeverityCRITICAL

WeaknessCWE-502

CISA KEVNo

Affected1 vendor(s)

PublishedOct 1, 2021

Related CVEs (CWE-502)

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2021-41110 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.

← All Vulnerabilities·Search for CVE-2021-41110·NVD