Arbitrary code execution via unsafe YAML loading
Published Oct 26, 2021 · Updated Aug 4, 2024
Unsafe YAML deserialization in Nameko before 2.14.0 and 3.0.0rc0 through 3.0.0rc9 allows local users to execute arbitrary code. The configuration loader passes attacker-controlled YAML to PyYAML's unsafe parser, which instantiates Python objects and invokes callable gadgets such as exec. Exploitation requires a victim to run Nameko with a crafted configuration file; successful execution runs with the victim process's privileges.
Summary
What happened
Unsafe YAML deserialization in Nameko before 2.14.0 and 3.0.0rc0 through 3.0.0rc9 allows local users to execute arbitrary code. The configuration loader passes attacker-controlled YAML to PyYAML's unsafe parser, which instantiates Python objects and invokes callable gadgets such as exec. Exploitation requires a victim to run Nameko with a crafted configuration file; successful execution runs with the victim process's privileges.
The record
- CVE
- CVE-2021-41078
- Published
- Oct 26, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-502, CAPEC-586, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 26, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Malicious YAML configuration exampleproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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