CVE-2021-4235 : What You Need to Know
Discover how CVE-2021-4235 in gopkg.in/yaml.v2 leads to denial of service due to unbounded alias chasing in YAML files. Learn about the impact, affected versions, and mitigation steps.
A denial of service vulnerability in gopkg.in/yaml.v2 that allows an attacker to execute a DoS attack by exploiting unbounded alias chasing in a YAML file.
Understanding CVE-2021-4235
This CVE discloses a vulnerability in gopkg.in/yaml.v2 that can lead to a denial of service due to unbounded alias chasing.
What is CVE-2021-4235?
The vulnerability in gopkg.in/yaml.v2 allows a maliciously crafted YAML file to consume significant system resources, potentially leading to a denial of service attack when parsing user input.
The Impact of CVE-2021-4235
The impact of this vulnerability is severe as it can be exploited to exhaust system resources, causing a denial of service condition.
Technical Details of CVE-2021-4235
This section outlines the technical details related to the vulnerability in gopkg.in/yaml.v2.
Vulnerability Description
The vulnerability arises from unbounded alias chasing in a YAML file, enabling an attacker to cause resource exhaustion.
Affected Systems and Versions
- Affected Vendor: gopkg.in/yaml.v2
- Affected Product: gopkg.in/yaml.v2
- Versions Affected: Less than v2.2.3
Exploitation Mechanism
By crafting a malicious YAML file, threat actors can trigger the vulnerability, causing a denial of service.
Mitigation and Prevention
To secure systems from CVE-2021-4235, the following mitigation strategies are recommended.
Immediate Steps to Take
- Upgrade to version 2.2.3 or higher of gopkg.in/yaml.v2 to prevent exploitation.
- Disable parsing of untrusted YAML files.
Long-Term Security Practices
- Regularly update software dependencies to patched versions.
- Conduct security audits of YAML processing routines.
Patching and Updates
Stay informed about security advisories and promptly apply patches to mitigate this vulnerability.