CVE-2022-23653

 

Published at: - 24-02-2022 12:15

Last modified: - 10-01-2023 09:57

Total changes: - 4

Description

B2 Command Line Tool is the official command line tool for the backblaze cloud storage service. Linux and Mac releases of the B2 command-line tool version 3.2.0 and below contain a key disclosure vulnerability that, in certain conditions, can be exploited by local attackers through a time-of-check-time-of-use (TOCTOU) race condition. The command line tool saves API keys (and bucket name-to-id mapping) in a local database file (`$XDG_CONFIG_HOME/b2/account_info`, `~/.b2_account_info` or a user-defined path) when `b2 authorize-account` is first run. This happens regardless of whether a valid key is provided or not. When first created, the file is world readable and is (typically a few milliseconds) later altered to be private to the user. If the directory is readable by a local attacker and the user did not yet run `b2 authorize-account` then during the brief period between file creation and permission modification, a local attacker can race to open the file and maintain a handle to it. This allows the local attacker to read the contents after the file after the sensitive information has been saved to it. Users that have not yet run `b2 authorize-account` should upgrade to B2 Command-Line Tool v3.2.1 before running it. Users that have run `b2 authorize-account` are safe if at the time of the file creation no other local users had read access to the local configuration file. Users that have run `b2 authorize-account` where the designated path could be opened by another local user should upgrade to B2 Command-Line Tool v3.2.1 and remove the database and regenerate all application keys. Note that `b2 clear-account` does not remove the database file and it should not be used to ensure that all open handles to the file are invalidated. If B2 Command-Line Tool cannot be upgraded to v3.2.1 due to a dependency conflict, a binary release can be used instead. Alternatively a new version could be installed within a virtualenv, or the permissions can be changed to prevent local users from opening the database file.

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

 

Verification logic

 

Reference

• https://github.com/Backblaze/B2_Command_Line_Tool/security/advisories/GHSA-8wr4-2wm6-w3pr
• https://github.com/Backblaze/B2_Command_Line_Tool/commit/c74029f9f75065e8f7e3c3ec8e0a23fb8204feeb

 

Keywords

NVD

 

CVE-2022-23653

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures