Local agent crash via YAML parser use-after-free
Published Apr 4, 2025 · Updated Apr 7, 2025
Use-after-free in Fluent Bit 3.7.2 allows local users to crash the telemetry agent by loading a crafted YAML configuration. During YAML parsing, consume_event frees parser state that state_pop_with_cleanup later reads through cfl_list_size. Exploitation requires local low-privileged access and user interaction to supply the configuration; successful exploitation terminates the agent.
Summary
What happened
Use-after-free in Fluent Bit 3.7.2 allows local users to crash the telemetry agent by loading a crafted YAML configuration. During YAML parsing, consume_event frees parser state that state_pop_with_cleanup later reads through cfl_list_size. Exploitation requires local low-privileged access and user interaction to supply the configuration; successful exploitation terminates the agent.
The record
- CVE
- CVE-2025-29477
- Published
- Apr 4, 2025
- Updated
- Apr 7, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-400, T1489
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 4, 2025CVE publishedPublication date reported by the CVE source.
- Apr 7, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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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.
Public exploit references
- Fluent Bit YAML configuration use-after-free proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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