CVE-2020-7663 – websocket-extensions

Package

Manager: gem
Name: websocket-extensions
Vulnerable Version: >=0 <0.1.5

Severity

Level: High

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

EPSS: 0.00725 pctl0.71723

Details

Regular Expression Denial of Service in websocket-extensions (RubyGem) ### Impact The ReDoS flaw allows an attacker to exhaust the server's capacity to process incoming requests by sending a WebSocket handshake request containing a header of the following form: Sec-WebSocket-Extensions: a; b="\c\c\c\c\c\c\c\c\c\c ... That is, a header containing an unclosed string parameter value whose content is a repeating two-byte sequence of a backslash and some other character. The parser takes exponential time to reject this header as invalid, and this will block the processing of any other work on the same thread. Thus if you are running a single-threaded server, such a request can render your service completely unavailable. ### Patches Users should upgrade to version 0.1.5. ### Workarounds There are no known work-arounds other than disabling any public-facing WebSocket functionality you are operating. ### References - https://blog.jcoglan.com/2020/06/02/redos-vulnerability-in-websocket-extensions/

Metadata

Created: 2020-06-05T14:21:29Z
Modified: 2023-05-16T16:17:54Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2020/06/GHSA-g6wq-qcwm-j5g2/GHSA-g6wq-qcwm-j5g2.json
CWE IDs: ["CWE-400"]
Alternative ID: GHSA-g6wq-qcwm-j5g2
Finding: F002
Auto approve: 1