MEDIUM
CVE-2021-4235
NVD-CWE-noinfoPublished: December 27, 2022· Updated: Jun 17, 2026
5.5
CVSS v3.1
Official Description
Due to unbounded alias chasing, a maliciously crafted YAML file can cause the system to consume significant system resources. If parsing user input, this may be used as a denial of service vector.
Technical Analysis
CVE-2021-4235 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 5.5.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Affected Vendors & Products
yaml_project1 product(s)
yaml
Source: NVD CPE · 1 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (8)
→
https://github.com/go-yaml/yaml/commit/bb4e33bf68bf89cad44d386192cbed201f35b241Patch · Third Party Advisory
→
https://github.com/go-yaml/yaml/pull/375Exploit · Patch · Third Party Advisory
→
https://pkg.go.dev/vuln/GO-2021-0061Third Party Advisory
→
https://github.com/go-yaml/yaml/commit/bb4e33bf68bf89cad44d386192cbed201f35b241Patch · Third Party Advisory
→
https://github.com/go-yaml/yaml/pull/375Exploit · Patch · Third Party Advisory
→
https://pkg.go.dev/vuln/GO-2021-0061Third Party Advisory
Quick Facts
CVE IDCVE-2021-4235
CVSS Score5.5 / 10
SeverityMEDIUM
WeaknessNVD-CWE-noinfo
CISA KEVNo
Affected1 vendor(s)
PublishedDec 27, 2022
Related CVEs (NVD-CWE-noinfo)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-4235 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.