CVE-2021-4235
Denial of service in gopkg.in/yaml.v2
Public exploit available. Not confirmed exploited in the wild yet. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
1 source with a proof of concept or module.
Exploit links, PoCs and Metasploit modules after sign-in- EPSS
0.4% chance of exploitation activity in the next 30 days, which ranks it in the 33rd percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
The patch came 329 days before any public exploit.
- OpenVAS check added
- Public exploit / PoCsource: github-poc
- Patch availablerecord updated
- Publishedweakness classified
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Scored 5.5 by NVD.
How it is reached
- Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction RequiredA user must click a link, open a file, or perform some action
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality NoneNo confidentiality impact
- Integrity NoneNo integrity impact
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
Sources
References in the record
- github.com/go-yaml/yaml/pull/375
- github.com/go-yaml/yaml/commit/bb4e33bf68bf89cad44d386192cbed201f35b241
- pkg.go.dev/vuln/GO-2021-0061
And 3 more references. See all after sign-in
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