SB2018101610 - Infinite loop in asciidoctor asciidoctor



SB2018101610 - Infinite loop in asciidoctor asciidoctor

Published: October 16, 2018 Updated: July 17, 2020

Security Bulletin ID SB2018101610
Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Infinite loop (CVE-ID: CVE-2018-18385)

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

Asciidoctor in versions < 1.5.8 allows remote attackers to cause a denial of service (infinite loop). The loop was caused by the fact that Parser.next_block was not exhausting all the lines in the reader as the while loop expected it would. This was happening because the regular expression that detects any list was not agreeing with the regular expression that detects a specific list type. So the line kept getting pushed back onto the reader, hence causing the loop.


Remediation

Install update from vendor's website.