Reported

November 14, 2021

Issued

November 18, 2021 (last modified: June 13, 2023)

Package

simple_asn1 (crates.io)

Type

Vulnerability

Categories

• denial-of-service

Keywords

#panic #string_slice

Aliases

• CVE-2021-45711
• GHSA-3m6f-3gfg-4x56
• GHSA-g4h2-4wvh-grc5

References

• https://github.com/acw/simple_asn1/issues/27

Patched

• >=0.6.1

Unaffected

• <0.6.0

Description

Version 0.6.0 of the simple_asn1 crate panics on certain malformed inputs to its parsing functions, including from_der and der_decode. Because this crate is frequently used with inputs from the network, this should be considered a security vulnerability.

The issue occurs when parsing the old ASN.1 "UTCTime" time format. If an attacker provides a UTCTime where the first character is ASCII but the second character is above 0x7f, a string slice operation in the from_der_ function will try to slice into the middle of a UTF-8 character, and cause a panic.

This error was introduced in commit d7d39d709577710e9dc8, which updated simple_asn1 to use time instead of chrono because of RUSTSEC-2020-159. Versions of simple_asn1 before 0.6.0 are not affected by this issue.

The patch was applied in simple_asn1 version 0.6.1.

Advisory available under CC0-1.0 license.