CVE-2021-40153

squashfs_opendir in unsquash-1.c in Squashfs-Tools 4.5 stores the filename in the directory entry; this is then used by unsquashfs to create the new file during the unsquash. The filename is not validated for traversal outside of the destination directory, and thus allows writing to locations outside of the destination.

squashfs_opendir in unsquash-1.c in Squashfs-Tools 4.5 stores the filename in the directory entry; this is then used by unsquashfs to create the new file during the unsquash. The filename is not validated for traversal outside of the destination directory, and thus allows writing to locations outside of the destination.

Squashfs is a highly compressed read-only filesystem for Linux. It uses either gzip/xz/lzo/lz4/zstd compression to compress both files, inodes and directories.

Security Fix(es):

squashfs_opendir in unsquash-2.c in Squashfs-Tools 4.5 allows Directory Traversal, a different vulnerability than CVE-2021-40153. A squashfs filesystem that has been crafted to include a symbolic link and then contents under the same filename in a filesystem can cause unsquashfs to first create the symbolic link pointing outside the expected directory, and then the subsequent write operation will cause the unsquashfs process to write through the symbolic link elsewhere in the filesystem.(CVE-2021-41072)

squashfs_opendir in unsquash-1.c in Squashfs-Tools 4.5 stores the filename in the directory entry; this is then used by unsquashfs to create the new file during the unsquash. The filename is not validated for traversal outside of the destination directory, and thus allows writing to locations outside of the destination.(CVE-2021-40153)

SquashFS is a highly compressed read-only file system for Linux. These packages contain the utilities for manipulating squashfs file systems.

Security Fix(es):

• squashfs-tools: unvalidated filepaths allow writing outside of destination (CVE-2021-40153)

• squashfs-tools: possible Directory Traversal via symbolic link (CVE-2021-41072)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 9.4 Release Notes linked from the References section.

squashfs_opendir in unsquash-1.c in Squashfs-Tools 4.5 stores the filename in the directory entry; this is then used by unsquashfs to create the new file during the unsquash. The filename is not validated for traversal outside of the destination directory, and thus allows writing to locations outside of the destination.

SquashFS is a highly compressed read-only file system for Linux. These packages contain the utilities for manipulating squashfs file systems.

Security Fix(es):

• squashfs-tools: unvalidated filepaths allow writing outside of destination (CVE-2021-40153)
• squashfs-tools: possible Directory Traversal via symbolic link (CVE-2021-41072)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

SquashFS is a highly compressed read-only file system for Linux. These packages contain the utilities for manipulating squashfs file systems.

Security Fix(es):

• squashfs-tools: unvalidated filepaths allow writing outside of destination (CVE-2021-40153)
• squashfs-tools: possible Directory Traversal via symbolic link (CVE-2021-41072)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

• CVE-2021-40153: fix directory traversal vulnerability in squashfs_opendir by validating filenames before creating new files

• CVE-2021-40153: fix write outside destination directory in unsquashfs

• CVE-2021-40153: fix write outside destination directory in unsquashfs

• CVE-2021-40153: fix write outside destination directory in unsquashfs

squashfs_opendir in unsquash-1.c in Squashfs-Tools 4.5 stores the filename in the directory entry; this is then used by unsquashfs to create the new file during the unsquash. The filename is not validated for traversal outside of the destination directory, and thus allows writing to locations outside of the destination. (CVE-2021-40153) squashfs_opendir in unsquash-2.c in Squashfs-Tools 4.5 allows Directory Traversal, a different vulnerability than CVE-2021-40153. A squashfs filesystem that has been crafted to include a symbolic link and then contents under the same filename in a filesystem can cause unsquashfs to first create the symbolic link pointing outside the expected directory, and then the subsequent write operation will cause the unsquashfs process to write through the symbolic link elsewhere in the filesystem. (CVE-2021-41072)

These are all security issues fixed in the squashfs-4.6.1-2.1 package on the GA media of openSUSE Tumbleweed.

SquashFS is a highly compressed read-only file system for Linux. These packages contain the utilities for manipulating squashfs file systems.

Security Fix(es):

• squashfs-tools: unvalidated filepaths allow writing outside of destination (CVE-2021-40153)

• squashfs-tools: possible Directory Traversal via symbolic link (CVE-2021-41072)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 8.10 Release Notes linked from the References section.

This update for squashfs fixes the following issues:

• CVE-2015-4645,CVE-2015-4646: Multiple buffer overflows fixed in squashfs-tools (bsc#935380)
• CVE-2021-40153: Fixed an issue where an attacker might have been able to write a file outside of destination (bsc#1189936)
• CVE-2021-41072: Fixed an issue where an attacker might have been able to write a file outside the destination directory via a symlink (bsc#1190531).

This update for squashfs fixes the following issues:

• CVE-2015-4645,CVE-2015-4646: Multiple buffer overflows fixed in squashfs-tools (bsc#935380)
• CVE-2021-40153: Fixed an issue where an attacker might have been able to write a file outside of destination (bsc#1189936)
• CVE-2021-41072: Fixed an issue where an attacker might have been able to write a file outside the destination directory via a symlink (bsc#1190531).

update to 4.6.1:

• Race condition which can cause corruption of the 'fragment table' fixed. This is a regression introduced in August 2022, and it has been seen when tailend packing is used (-tailends option).
• Fix build failure when the tools are being built without extended attribute (XATTRs) support.
• Fix XATTR error message when an unrecognised prefix is found
• Fix incorrect free of pointer when an unrecognised XATTR prefix is found.
• Major improvements in extended attribute handling, pseudo file handling, and miscellaneous new options and improvements
• Extended attribute handling improved in Mksquashfs and Sqfstar
• New Pseudo file xattr definition to add extended attributes to files.
• New xattrs-add Action to add extended attributes to files
• Extended attribute handling improved in Unsquashfs
• Other major improvements
• Unsquashfs can now output Pseudo files to standard out.
• Mksquashfs can now input Pseudo files from standard in.
• Squashfs filesystems can now be converted (different block size compression etc) without unpacking to an intermediate filesystem or mounting, by piping the output of Unsquashfs to Mksquashfs.
• Pseudo files are now supported by Sqfstar.
• 'Non-anchored' excludes are now supported by Unsquashfs.

update to 4.5.1 (bsc#1190531, CVE-2021-41072):

• This release adds Manpages for Mksquashfs(1), Unsquashfs(1), Sqfstar(1) and Sqfscat(1).
• The -help text output from the utilities has been improved and extended as well (but the Manpages are now more comprehensive).
• CVE-2021-41072 which is a writing outside of destination exploit, has been fixed.
• The number of hard-links in the filesystem is now also displayed by Mksquashfs in the output summary.
• The number of hard-links written by Unsquashfs is now also displayed in the output summary.
• Unsquashfs will now write to a pre-existing destination directory, rather than aborting.
• Unsquashfs now allows '.' to used as the destination, to extract to the current directory.
• The Unsquashfs progress bar now tracks empty files and hardlinks, in addition to data blocks.
• -no-hardlinks option has been implemented for Sqfstar.
• More sanity checking for 'corrupted' filesystems, including checks for multiply linked directories and directory loops.
• Options that may cause filesystems to be unmountable have been moved into a new 'experts' category in the Mksquashfs help text (and Manpage).
• Maximum cpiostyle filename limited to PATH_MAX. This prevents attempts to overflow the stack, or cause system calls to fail with a too long pathname.
• Don't always use 'max open file limit' when calculating length of queues, as a very large file limit can cause Unsquashfs to abort. Instead use the smaller of max open file limit and cache size.
• Fix Mksquashfs silently ignoring Pseudo file definitions when appending.
• Don't abort if no XATTR support has been built in, and there's XATTRs in the filesystem. This is a regression introduced in 2019 in Version 4.4.
• Fix duplicate check when the last file block is sparse.

update to 4.5:

• Mksquashfs now supports 'Actions'.
• New sqfstar command which will create a Squashfs image from a tar archive.
• Tar style handling of source pathnames in Mksquashfs.
• Cpio style handling of source pathnames in Mksquashfs.
• New option to throttle the amount of CPU and I/O.
• Mksquashfs now allows no…

This update for squashfs fixes the following issues:

• CVE-2015-4645,CVE-2015-4646: Multiple buffer overflows fixed in squashfs-tools (bsc#935380)
• CVE-2021-40153: Fixed an issue where an attacker might have been able to write a file outside of destination (bsc#1189936)
• CVE-2021-41072: Fixed an issue where an attacker might have been able to write a file outside the destination directory via a symlink (bsc#1190531).

update to 4.6.1:

• Race condition which can cause corruption of the 'fragment table' fixed. This is a regression introduced in August 2022, and it has been seen when tailend packing is used (-tailends option).
• Fix build failure when the tools are being built without extended attribute (XATTRs) support.
• Fix XATTR error message when an unrecognised prefix is found
• Fix incorrect free of pointer when an unrecognised XATTR prefix is found.
• Major improvements in extended attribute handling, pseudo file handling, and miscellaneous new options and improvements
• Extended attribute handling improved in Mksquashfs and Sqfstar
• New Pseudo file xattr definition to add extended attributes to files.
• New xattrs-add Action to add extended attributes to files
• Extended attribute handling improved in Unsquashfs
• Other major improvements
• Unsquashfs can now output Pseudo files to standard out.
• Mksquashfs can now input Pseudo files from standard in.
• Squashfs filesystems can now be converted (different block size compression etc) without unpacking to an intermediate filesystem or mounting, by piping the output of Unsquashfs to Mksquashfs.
• Pseudo files are now supported by Sqfstar.
• 'Non-anchored' excludes are now supported by Unsquashfs.

update to 4.5.1 (bsc#1190531, CVE-2021-41072):

• This release adds Manpages for Mksquashfs(1), Unsquashfs(1), Sqfstar(1) and Sqfscat(1).
• The -help text output from the utilities has been improved and extended as well (but the Manpages are now more comprehensive).
• CVE-2021-41072 which is a writing outside of destination exploit, has been fixed.
• The number of hard-links in the filesystem is now also displayed by Mksquashfs in the output summary.
• The number of hard-links written by Unsquashfs is now also displayed in the output summary.
• Unsquashfs will now write to a pre-existing destination directory, rather than aborting.
• Unsquashfs now allows '.' to used as the destination, to extract to the current directory.
• The Unsquashfs progress bar now tracks empty files and hardlinks, in addition to data blocks.
• -no-hardlinks option has been implemented for Sqfstar.
• More sanity checking for 'corrupted' filesystems, including checks for multiply linked directories and directory loops.
• Options that may cause filesystems to be unmountable have been moved into a new 'experts' category in the Mksquashfs help text (and Manpage).
• Maximum cpiostyle filename limited to PATH_MAX. This prevents attempts to overflow the stack, or cause system calls to fail with a too long pathname.
• Don't always use 'max open file limit' when calculating length of queues, as a very large file limit can cause Unsquashfs to abort. Instead use the smaller of max open file limit and cache size.
• Fix Mksquashfs silently ignoring Pseudo file definitions when appending.
• Don't abort if no XATTR support has been built in, and there's XATTRs in the filesystem. This is a regression introduced in 2019 in Version 4.4.
• Fix duplicate check when the last file block is sparse.

update to 4.5:

• Mksquashfs now supports 'Actions'.
• New sqfstar command which will create a Squashfs image from a tar archive.
• Tar style handling of source pathnames in Mksquashfs.
• Cpio style handling of source pathnames in Mksquashfs.
• New option to throttle the amount of CPU and I/O.
• Mksquashfs now allows no…

Etienne Stalmans discovered that Squashfs-Tools mishandled certain malformed SQUASHFS files. An attacker could use this vulnerability to write arbitrary files to the filesystem.

USN-5078-1 fixed several vulnerabilities in Squashfs-Tools. This update provides the corresponding update for Ubuntu 16.04 ESM.

Original advisory details:

Etienne Stalmans discovered that Squashfs-Tools mishandled certain malformed SQUASHFS files. An attacker could use this vulnerability to write arbitrary files to the filesystem. (CVE-2021-40153)

Richard Weinberger discovered that Squashfs-Tools mishandled certain malformed SQUASHFS files. An attacker could use this vulnerability to write arbitrary files to the filesystem. (CVE-2021-41072)