CVE-2022-40023

Sqlalchemy mako before 1.2.2 is vulnerable to Regular expression Denial of Service when using the Lexer class to parse. This also affects babelplugin and linguaplugin.

Weakness

The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.

Affected Software

Extended Description

      Attackers can create crafted inputs that
      intentionally cause the regular expression to use
      excessive backtracking in a way that causes the CPU
      consumption to spike.

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/492.html

References

• https://github.com/sqlalchemy/mako/commit/925760291d6efec64fda6e9dd1fd9cfbd5be068c
• https://pyup.io/vulnerabilities/CVE-2022-40023/50870/
• https://github.com/sqlalchemy/mako/issues/366
• https://github.com/sqlalchemy/mako/blob/c2f392e0be52dc67d1b9770ab8cce6a9c736d547/mako/ext/extract.py#L21
• https://lists.debian.org/debian-lts-announce/2022/09/msg00026.html
• https://pyup.io/posts/pyup-discovers-redos-vulnerabilities-in-top-python-packages/