CVE-2021-4235
Publication date 27 December 2022
Last updated 24 June 2025
Ubuntu priority
Cvss 3 Severity Score
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.
Status
| Package | Ubuntu Release | Status | 
|---|---|---|
| golang-github-coreos-discovery-etcd-io | 25.10 questing | 
                                Vulnerable 
                                
                               | 
| 25.04 plucky | 
                                Vulnerable 
                                
                               | |
| 24.04 LTS noble | 
                                Vulnerable 
                                
                               | |
| 22.04 LTS jammy | 
                                Vulnerable 
                                
                               | |
| 20.04 LTS focal | 
                                Vulnerable 
                                
                               | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Ignored end of standard support | |
| 14.04 LTS trusty | Ignored end of standard support | |
| golang-gopkg-yaml.v3 | 25.10 questing | 
                                Not affected 
                                
                               | 
| 25.04 plucky | 
                                Not affected 
                                
                               | |
| 24.04 LTS noble | 
                                Not affected 
                                
                               | |
| 22.04 LTS jammy | 
                                Not affected 
                                
                               | |
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Ignored end of standard support | |
| 14.04 LTS trusty | Ignored end of standard support | |
| golang-yaml.v2 | 25.10 questing | 
                                Not affected 
                                
                               | 
| 25.04 plucky | 
                                Not affected 
                                
                               | |
| 24.04 LTS noble | 
                                Not affected 
                                
                               | |
| 22.04 LTS jammy | 
                                Not affected 
                                
                               | |
| 20.04 LTS focal | 
                                Fixed 2.2.2-1ubuntu0.1 
                                
                               | |
| 18.04 LTS bionic | 
                                Fixed 0.0+git20170407.0.cd8b52f-1ubuntu2+esm1 
                                
                                   | |
| 16.04 LTS xenial | 
                                Fixed 0.0+git20160301.0.a83829b-1ubuntu0.1~esm1 
                                
                                   | |
| 14.04 LTS trusty | Ignored end of standard support | |
| kubernetes | 25.10 questing | Not in release | 
| 25.04 plucky | Not in release | |
| 24.04 LTS noble | 
                                Not affected 
                                
                               | |
| 22.04 LTS jammy | 
                                Not affected 
                                
                               | |
| 20.04 LTS focal | 
                                Not affected 
                                
                               | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Ignored end of standard support | |
| 14.04 LTS trusty | Ignored end of standard support | |
| singularity-container | 25.10 questing | 
                                Needs evaluation 
                                
                               | 
| 25.04 plucky | 
                                Needs evaluation 
                                
                               | |
| 24.04 LTS noble | 
                                Needs evaluation 
                                
                               | |
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | 
                                Needs evaluation 
                                
                               | |
| 16.04 LTS xenial | Ignored end of standard support | |
| 14.04 LTS trusty | Ignored end of standard support | |
| webhook | 25.10 questing | 
                                Needs evaluation 
                                
                               | 
| 25.04 plucky | 
                                Needs evaluation 
                                
                               | |
| 24.04 LTS noble | 
                                Needs evaluation 
                                
                               | |
| 22.04 LTS jammy | 
                                Needs evaluation 
                                
                               | |
| 20.04 LTS focal | 
                                Needs evaluation 
                                
                               | |
| 18.04 LTS bionic | 
                                Needs evaluation 
                                
                               | |
| 16.04 LTS xenial | Ignored end of standard support | |
| 14.04 LTS trusty | Ignored end of standard support | 
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leosilva
kubernates is in fact a kubernetes installer that calls snap, not the package it self.
allenpthuang
golang-github-coreos-discovery-etcd-io is potentially affected due to vendored go-yaml in vendor/gopkg.in/yaml.v2
Severity score breakdown
| Parameter | Value | 
|---|---|
| Base score |  | 
| Attack vector | Local | 
| Attack complexity | Low | 
| Privileges required | None | 
| User interaction | Required | 
| Scope | Unchanged | 
| Confidentiality | None | 
| Integrity impact | None | 
| Availability impact | High | 
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H | 
References
Related Ubuntu Security Notices (USN)
- USN-6287-1
- Go yaml vulnerabilities
- 14 August 2023