Ddos 
A newly disclosed vulnerability in dpkg-deb, the core utility responsible for handling Debian package archives, has raised concerns over potential Denial-of-Service (DoS) conditions caused by incomplete cleanup of temporary files. Tracked as CVE-2025-6297, the flaw carries a CVSS score of 8.2, reflecting its moderate to high severity under specific conditions.
The issue arises from the improper sanitization of directory permissions during the extraction of a control member (a metadata file in .deb packages) into a temporary directory. This operation is explicitly documented as safe, even on untrusted input. However, as the advisory points out:
“The code in charge of the temporary directory cleanup does not sanitize the directory permissions, which is then unable to perform the ‘rm -rf’ when running as a non-root user, leaving temporary files behind.”
These leftover files, under normal circumstances, pose little threat. But in automated environments—such as build systems, package scanners, or CI/CD pipelines—where malicious or overly compressible .deb files may be repeatedly processed, the results can be catastrophic.
“Given automated and repeated execution… this can end up in a DoS scenario due to causing disk quota exhaustion or disk full conditions,” reads the CVE description.
This vulnerability doesn’t allow privilege escalation or remote code execution. However, by carefully crafting .deb packages and placing them in directories with restrictive permissions (preventing file deletion by non-root users), an attacker could trigger a persistent buildup of temporary files.
Over time—or even quickly, if files are large or easily compressible—this accumulation can lead to:
- Exhaustion of disk quota
- Disk full errors
- System instability or failure of services reliant on the filesystem
These symptoms are especially dangerous in shared-hosting environments, multi-user systems, or automation-heavy infrastructures.
Although considered “a minor issue” by the maintainers, the vulnerability violates the security guarantees explicitly documented by the tool. dpkg-deb is assumed to safely handle untrusted data in controlled, temporary spaces. As the advisory notes:
“This has been an issue since the initial commit introducing dpkg-deb in C.”
Its persistence across decades of use—and the potential for quiet exploitation in resource-limited environments—makes it more than a mere annoyance.
Administrators and developers should:
- Update to the latest patched version of dpkg-deb when available
- Monitor disk usage and watch for unusually persistent files in temporary directories
- Avoid running dpkg-deb repeatedly on untrusted or user-submitted packages, especially in automated environments
- Enforce disk quotas and logging to detect abnormal growth in temporary directories
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