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.
CVSS Score
4.4
EPSS Score
0.001
Published
2026-08-03
A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.
CVSS Score
4.4
EPSS Score
0.001
Published
2026-08-03
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.
CVSS Score
5.0
EPSS Score
0.004
Published
2026-04-06
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/authorized_keys. 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.
CVSS Score
4.1
EPSS Score
0.004
Published
2025-07-11
In GNU tar before 1.35, mishandled extension attributes in a PAX archive can lead to an application crash in xheader.c.
CVSS Score
6.2
EPSS Score
0.003
Published
2024-03-27
GNU Tar through 1.34 has a one-byte out-of-bounds read that results in use of uninitialized memory for a conditional jump. Exploitation to change the flow of control has not been demonstrated. The issue occurs in from_header in list.c via a V7 archive in which mtime has approximately 11 whitespace characters.
CVSS Score
5.5
EPSS Score
0.015
Published
2023-01-30
A flaw was found in the src/list.c of tar 1.33 and earlier. This flaw allows an attacker who can submit a crafted input file to tar to cause uncontrolled consumption of memory. The highest threat from this vulnerability is to system availability.
CVSS Score
3.3
EPSS Score
0.011
Published
2021-03-26
pax_decode_header in sparse.c in GNU Tar before 1.32 had a NULL pointer dereference when parsing certain archives that have malformed extended headers.
CVSS Score
7.5
EPSS Score
0.03
Published
2019-03-22
GNU Tar through 1.30, when --sparse is used, mishandles file shrinkage during read access, which allows local users to cause a denial of service (infinite read loop in sparse_dump_region in sparse.c) by modifying a file that is supposed to be archived by a different user's process (e.g., a system backup running as root).
CVSS Score
4.7
EPSS Score
0.005
Published
2018-12-26
Directory traversal vulnerability in the safer_name_suffix function in GNU tar 1.14 through 1.29 might allow remote attackers to bypass an intended protection mechanism and write to arbitrary files via vectors related to improper sanitization of the file_name parameter, aka POINTYFEATHER.
CVSS Score
7.5
EPSS Score
0.136
Published
2016-12-09
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