CVE-2021-4235

MEDIUM

yaml < 2.2.3 - Denial of Service via Unbounded Alias Chasing

Title source: llm

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.

References (4)

Core 4

Core References

Patch, Third Party Advisory

https://github.com/go-yaml/yaml/commit/bb4e33bf68bf89cad44d386192cbed201f35b241

View Patch ZIP pw:eip

Exploit, Patch, Third Party Advisory

https://github.com/go-yaml/yaml/pull/375

Third Party Advisory

https://pkg.go.dev/vuln/GO-2021-0061

Mailing List

https://lists.debian.org/debian-lts-announce/2023/07/msg00001.html

Scores

CVSS v3 5.5

EPSS 0.0042

EPSS Percentile 33.4%

Attack Vector LOCAL

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

CISA SSVC

Vulnrichment

Exploitation poc

Automatable no

Technical Impact partial

Details

Status published

Products (3)

go-yaml/yaml 0Go

gopkg.in/yaml.v2 0 - 2.2.3Go

yaml_project/yaml < 2.2.3

Published Dec 27, 2022

Tracked Since Feb 18, 2026