A flaw was found in GNU tar. The --one-top-level option is intended to confine extraction under a designated directory, but hardlink targets from the archive are not confined the same way and are resolved relative to the extraction working directory (or the directory given with -C). A crafted archive can create hardlinks inside the --one-top-level directory that point to files outside it. If a suitable symbolic link already exists under the extraction working directory, hardlinking to that symlink can bypass tar's usual symlink-based path protections and allow writing outside the intended top-level directory during a single extraction. Users who rely on --one-top-level as a security boundary when extracting untrusted archives may be affected.
tar.Reader does not set a maximum size on the number of sparse region data blocks in GNU tar pax 1.0 sparse files. A maliciously-crafted archive containing a large number of sparse regions can cause a Reader to read an unbounded amount of data from the archive into memory. When reading from a compressed source, a small compressed input can result in large allocations.
A TOCTOU (Time-of-Check Time-of-Use) vulnerability in GNU tar's incremental dumpdir 'X' rename handling allows a local attacker with write access to a directory being backed up to influence the restore process if the attacker has access to the system where the restore is being performed. During restoration, files or directories may be created, renamed or overwritten outside the intended extraction directory. This could lead to unauthorized file modification or, in some cases, privilege escalation. Exploitation does not require the attacker to modify or craft the archive, and standard backup and restore workflows—including extracting into a newly created directory without using the -P option do not mitigate the issue.
In GNU tar before 1.35 mishandled extension attributes in a PAX archive can lead to an application crash in xheader.c.
A flaw was found in GNU tar. The --one-top-level option is intended to confine extraction under a designated directory, but hardlink targets from the archive are not confined the same way and are resolved relative to the extraction working directory (or the directory given with -C). A crafted archive can create hardlinks inside the --one-top-level directory that point to files outside it. If a suitable symbolic link already exists under the extraction working directory, hardlinking to that symlink can bypass tar's usual symlink-based path protections and allow writing outside the intended top-level directory during a single extraction. Users who rely on --one-top-level as a security boundary when extracting untrusted archives may be affected.
A TOCTOU (Time-of-Check Time-of-Use) vulnerability in GNU tar's incremental dumpdir 'X' rename handling allows a local attacker with write access to a directory being backed up to influence the restore process if the attacker has access to the system where the restore is being performed. During restoration, files or directories may be created, renamed or overwritten outside the intended extraction directory. This could lead to unauthorized file modification or, in some cases, privilege escalation. Exploitation does not require the attacker to modify or craft the archive, and standard backup and restore workflows—including extracting into a newly created directory without using the -P option do not mitigate the issue.
A flaw was found in tar. A remote attacker could exploit this vulnerability by crafting a malicious archive, leading to hidden file injection with fully attacker-controlled content. This bypasses pre-extraction inspection mechanisms, potentially allowing an attacker to introduce malicious files onto a system without detection.
GNU Tar through 1.35 allows file overwrite via directory traversal in crafted TAR archives, with a certain two-step process. First, the victim must extract an archive that contains a ../ symlink to a critical directory. Second, the victim must extract an archive that contains a critical file, specified via a relative pathname that begins with the symlink name and ends with that critical file's name. Here, the extraction follows the symlink and overwrites the critical file. This bypasses the protection mechanism of "Member name contains '..'" that would occur for a single TAR archive that attempted to specify the critical file via a ../ approach. For example, the first archive can contain "x - ../../../../../home/victim/.ssh" and the second archive can contain x/authorizedkeys. This can affect server applications that automatically extract any number of user-supplied TAR archives, and were relying on the blocking of traversal. This can also affect software installation processes in which "tar xf" is run more than once (e.g., when installing a package can automatically install two dependencies that are set up as untrusted tarballs instead of official packages). NOTE: the official GNU Tar manual has an otherwise-empty directory for each "tar xf" in its Security Rules of Thumb; however, third-party advice leads users to run "tar xf" more than once into the same directory.
GNU Tar through 1.35 allows file overwrite via directory traversal in crafted TAR archives, with a certain two-step process. First, the victim must extract an archive that contains a ../ symlink to a critical directory. Second, the victim must extract an archive that contains a critical file, specified via a relative pathname that begins with the symlink name and ends with that critical file's name. Here, the extraction follows the symlink and overwrites the critical file. This bypasses the protection mechanism of "Member name contains '..'" that would occur for a single TAR archive that attempted to specify the critical file via a ../ approach. For example, the first archive can contain "x -> ../../../../../home/victim/.ssh" and the second archive can contain x/authorizedkeys. This can affect server applications that automatically extract any number of user-supplied TAR archives, and were relying on the blocking of traversal.
The unarchive internal module's archive extraction commands perform no code-level validation on extracted file paths, relying entirely on the behavior of external tools (e.g. GNU tar) which varies by platform. While CVE-2025-10284 addressed git-specific RCE vectors, the underlying archive extraction path traversal was never fixed. On systems with GNU tar < 1.34 (Ubuntu 20.04, Debian Buster, CentOS 7, many Docker base images), a malicious archive can write files outside the intended extraction directory.
A heap-based buffer overflow flaw was found in the way tar and cpio archive manipulation tools expanded archives with certain character in the archive name. If a local user was tricked into expanding a specially-crafted archive, it could cause the tar, cpio executables to crash or, potentially, to execute arbitrary code with the privileges of the user running the utility.
Link to advisory: [1] http://www.agrs.tu-berlin.de/index.php?id=78327
Acknowledgements:
Red Hat would like to thank Jakob Lell for responsibly reporting this issue.
GNU tar 1.16 and 1.15.1, and possibly other versions, allows user-assisted attackers to overwrite arbitrary files via a tar file that contains a GNUTYPENAMES record with a symbolic link, which is not properly handled by the extractarchive function in extract.c and extractmangle function in mangle.c, a variant of CVE-2002-1216.
Flaw bug created to hold information about an old flaw we knew something about. For more details see the MITRE CVE description.
Directory traversal vulnerability in GNU tar 1.13.19 through 1.13.25, and possibly later versions, allows attackers to overwrite arbitrary files during archive extraction via a (1) "/.." or (2) "./.." string, which removes the leading slash but leaves the "..", a variant of CVE-2001-1267.
Buffer overflow in tar 1.14 through 1.15.90 allows user-assisted attackers to cause a denial of service (application crash) and possibly execute code via unspecified vectors involving PAX extended headers.
Directory traversal vulnerability in the containsdotdot function in src/names.c in GNU tar allows user-assisted remote attackers to overwrite arbitrary files via certain //.. (slash slash dot dot) sequences in directory symlinks in a TAR archive.