Overview
This article discusses CVE-2025-65100, a vulnerability found in Isar, an integration system designed for automated root filesystem generation. The vulnerability arises from an incorrect timestamp setting for the security distribution when only defining `ISAR_APT_SNAPSHOT_DATE`. This misconfiguration can lead to missed security updates within the generated root filesystem.
This issue affects Isar versions 0.11-rc1 and 0.11. A patch has been released to address this vulnerability.
Technical Details
The core of the problem lies in how Isar handles APT snapshot dates. When the `ISAR_APT_SNAPSHOT_DATE` variable is defined in the affected versions, it does not fully propagate the correct timestamp information required for APT to accurately determine the availability of security updates from the distribution’s repositories. This leads to APT potentially ignoring available security patches, leaving the system vulnerable.
The fix, implemented via commit 738bcbb, corrects this behavior, ensuring proper timestamping for security distributions when using `ISAR_APT_SNAPSHOT_DATE`.
CVSS Analysis
Currently, a CVSS score and severity rating are not available for CVE-2025-65100. However, the potential impact of missed security updates should be considered significant, as it could leave systems vulnerable to known exploits. Users are advised to promptly apply the available patch.
Possible Impact
The primary impact of this vulnerability is the potential for systems built using Isar to miss critical security updates. This can expose affected systems to a range of security risks, including:
- Remote code execution
- Denial-of-service attacks
- Data breaches
- Privilege escalation
The specific impact will depend on the vulnerabilities present in the software installed within the generated root filesystem.
Mitigation or Patch Steps
The recommended solution is to update Isar to a version containing the fix for CVE-2025-65100. Specifically, ensure that the commit 738bcbb is included in your Isar installation. This can typically be achieved by:
- Cloning the latest Isar repository from GitHub: `git clone https://github.com/ilbers/isar.git`
- Verifying that the commit `738bcbb716c7eb7b34cbb2293cae4f264b3925fe` is present in the commit history.
- Rebuilding your root filesystem using the updated Isar version.
If upgrading Isar directly is not immediately feasible, investigate workarounds or manual configuration changes to ensure proper APT snapshot date handling until the update can be applied.
References
- CVE ID: CVE-2025-65100 (Note: CVE may not exist, it is just a placeholder)
- GitHub Commit (Fix): https://github.com/ilbers/isar/commit/738bcbb716c7eb7b34cbb2293cae4f264b3925fe
- GitHub Commit (Related): https://github.com/ilbers/isar/commit/3383fd808a4ced93e41e012660dfe364a3384434
- GitHub Security Advisory: https://github.com/ilbers/isar/security/advisories/GHSA-3r9w-6cp6-7hm4
