SecuriTricks - CVE-2025-12972

Description

Fluent Bit out_file plugin does not properly sanitize tag values when deriving output file names. When the File option is omitted, the plugin uses untrusted tag input to construct file paths. This allows attackers with network access to craft tags containing path traversal sequences that cause Fluent Bit to write files outside the intended output directory.

Product(s) Impacted

Vendor	Product	Versions
Treasuredata	Fluent Bit	4.1.0

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	treasuredata	fluent_bit	4.1.0	/	/	/	/	/	/	/

References

https://fluentbit.io/blog/2025/10/28/security-vulnerabilities-addressed-in-fluent-bit-v4.1-and-backported-to-v4.0/

https://www.oligo.security/blog/critical-vulnerabilities-in-fluent-bit-expose-cloud-environments-to-remote-takeover

CVSS Score

5.3 / 10

CVSS Data - 3.1

Attack Vector: NETWORK
Attack Complexity: LOW
Privileges Required: NONE
Scope: UNCHANGED
Confidentiality Impact: NONE
Integrity Impact: LOW
Availability Impact: NONE

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

View Vector String

Timeline

Published: Nov. 24, 2025, 3:15 p.m.
Last Modified: Nov. 28, 2025, 6:15 p.m.

Status : Modified

CVE has been amended by a source (CVE Primary CNA or another CNA). Analysis data supplied by the NVD may be no longer be accurate due to these changes.

More info

Source

cret@cert.org

CVE-2025-12972