A deserialization vulnerability exists in the way parso through 0.4.0...

Vulnerability Description

A deserialization vulnerability exists in the way parso through 0.4.0 handles grammar parsing from the cache. Cache loading relies on pickle and, provided that an evil pickle can be written to a cache grammar file and that its parsing can be triggered, this flaw leads to Arbitrary Code Execution. NOTE: This is disputed because "the cache directory is not under control of the attacker in any common configuration.

References

• https://gist.github.com/dhondta/f71ae7e5c4234f8edfd2f12503a5dcc7
• https://github.com/davidhalter/parso/issues/75