CVE-2019-19039

__btrfs_free_extent in fs/btrfs/extent-tree.c in the Linux kernel through 5.3.12 calls btrfs_print_leaf in a certain ENOENT case, which allows local users to obtain potentially sensitive information about register values via the dmesg program. NOTE: The BTRFS development team disputes this issues as not being a vulnerability because “1) The kernel provide facilities to restrict access to dmesg - dmesg_restrict=1 sysctl option. So its really up to the system administrator to judge whether dmesg access shall be disallowed or not. 2) WARN/WARN_ON are widely used macros in the linux kernel. If this CVE is considered valid this would mean there are literally thousands CVE lurking in the kernel - something which clearly is not the case.

Weakness

Information written to log files can be of a sensitive nature and give valuable guidance to an attacker or expose sensitive user information.

Affected Software

Extended Description

While logging all information may be helpful during development stages, it is important that logging levels be set appropriately before a product ships so that sensitive user data and system information are not accidentally exposed to potential attackers. Different log files may be produced and stored for:

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/215.html

References

• https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19039
• https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html
• https://usn.ubuntu.com/4414-1/