RUSTSEC-2021-0027

Loading a bgzip block can write out of bounds if size overflows.

Reported

January 7, 2021

Issued

March 1, 2021 (last modified: October 19, 2021)

Package

bam (crates.io)

Type

Vulnerability

Categories

memory-corruption

Aliases

CVE-2021-28027

Details

https://gitlab.com/tprodanov/bam/-/issues/4

CVSS Score

9.8 CRITICAL

CVSS Details

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

CVSS Vector

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

Patched

>=0.1.3

Affected Functions

Version

bam::bgzip::Block::load

<0.1.3

Description

Affected versions of bam set the length of an internal buffer using self.compressed.set_len(block_size - HEADER_SIZE - MIN_EXTRA_SIZE) and then wrote into it. While block_size was constrained to a proper maximum, when it was too small the subtraction could overflow negatively to a large number past the capacity of self.compressed.

This can result in memory corruption in the form of writing out of bounds when loading a bgzip file with a small block_size.

Commit 061eee38d4 fixed this issue by checking for the underflow when setting the buffer size.