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melange's world-writable permissions expose SBOM files to potential image tampering

Moderate severity GitHub Reviewed Published Jul 18, 2025 in chainguard-dev/melange • Updated Jul 18, 2025

Package

gomod chainguard.dev/melange (Go)

Affected versions

>= 0.23.0, < 0.29.5

Patched versions

0.29.5

Description

It was discovered that the SBOM files generated by melange in apks had file system permissions mode 666:

$ apkrane ls https://packages.wolfi.dev/os/x86_64/APKINDEX.tar.gz -P hello-wolfi --full --latest  | xargs wget -q -O  - | tar tzv 2>/dev/null var/lib/db/sbom
drwxr-xr-x root/root         0 2025-06-23 14:17 var/lib/db/sbom
-rw-rw-rw- root/root      3383 2025-06-23 14:17 var/lib/db/sbom/hello-wolfi-2.12.2-r1.spdx.json

This issue was introduced in commit 1b272db ("Persist workspace filesystem throughout package builds (#1836)") (v0.23.0).

Impact

This potentially allows an unprivileged user to tamper with apk SBOMs on a running image, potentially confusing security scanners. An attacker could also perform a DoS under special circumstances.

Patches

This issue was addressed in melange in e29494b ("fix: tighten up permissions for written SBOM files and signature tarballs (#2086)") (v0.29.5).

Acknowledgements

Thanks to Cody Harris H2O.ai and Markus Boehme for independently reporting this issue.

References

@eslerm eslerm published to chainguard-dev/melange Jul 18, 2025
Published by the National Vulnerability Database Jul 18, 2025
Published to the GitHub Advisory Database Jul 18, 2025
Reviewed Jul 18, 2025
Last updated Jul 18, 2025

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(1st percentile)

Weaknesses

Incorrect Default Permissions

During installation, installed file permissions are set to allow anyone to modify those files. Learn more on MITRE.

CVE ID

CVE-2025-54059

GHSA ID

GHSA-5662-cv6m-63wh

Source code

Credits

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