advisory-db/crates/bam/RUSTSEC-2021-0027.md

[advisory]
id = "RUSTSEC-2021-0027"
package = "bam"
aliases = ["CVE-2021-28027"]
cvss = "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
date = "2021-01-07"
url = "https://gitlab.com/tprodanov/bam/-/issues/4"
categories = ["memory-corruption"]

[versions]
patched = [">= 0.1.3"]

[affected]
functions = { "bam::bgzip::Block::load" = ["< 0.1.3"] }

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

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.