RUSTSEC-2019-0010

MultiDecoder::read() drops uninitialized memory of arbitrary type on panic in client code

Issued
Package
libflate (crates.io)
Type
Vulnerability
Aliases
Details
https://github.com/sile/libflate/issues/35
Patched
  • >=0.1.25
Unaffected
  • <0.1.14
Keywords
  • drop
  • use-after-free
Affected Functions
Version
libflate::gzip::MultiDecoder::read
  • <0.1.25, >=0.1.14

Description

Affected versions of libflate have set a field of an internal structure with a generic type to an uninitialized value in MultiDecoder::read() and reverted it to the original value after the function completed. However, execution of MultiDecoder::read() could be interrupted by a panic in caller-supplied Read implementation. This would cause drop() to be called on uninitialized memory of a generic type implementing Read.

This is equivalent to a use-after-free vulnerability and could allow an attacker to gain arbitrary code execution.

The flaw was corrected by aborting immediately instead of unwinding the stack in case of panic within MultiDecoder::read(). The issue was discovered and fixed by Shnatsel.

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