Reported

September 17, 2018

Issued

October 2, 2020 (last modified: October 19, 2021)

Package

yaml-rust (crates.io)

Type

Vulnerability

Keywords

#crash

Aliases

• CVE-2018-20993

Details

https://github.com/chyh1990/yaml-rust/pull/109

CVSS Score

7.5 HIGH

CVSS Details

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

CVSS Vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Patched

• >=0.4.1

Description

Affected versions of this crate did not prevent deep recursion while deserializing data structures.

This allows an attacker to make a YAML file with deeply nested structures that causes an abort while deserializing it.

The flaw was corrected by checking the recursion depth.

Note: clap 2.33 is not affected by this because it uses yaml-rust in a way that doesn't trigger the vulnerability. More specifically:

1. The input to the YAML parser is always trusted - is included at compile time via include_str!.

2. The nesting level is never deep enough to trigger the overflow in practice (at most 5).