# CVE-2020-7663: ruby-websocket-extensions: websocket-extensions ruby module prior to 0.1.5 allows Denial of Service (DoS) via Regex Backtracking

CVE-2020-7663 is fixed in ruby-websocket-extensions on 1 platform, first by ruby-websocket-extensions 0.1.2-1+deb9u1build0.18.04.1, released June 2, 2020. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2020-7663
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0464
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 2, 2020

## Description

websocket-extensions ruby module prior to 0.1.5 allows Denial of Service (DoS) via Regex Backtracking. The extension parser may take quadratic time when parsing a header containing an unclosed string parameter value whose content is a repeating two-byte sequence of a backslash and some other character. This could be abused by an attacker to conduct Regex Denial Of Service (ReDoS) on a single-threaded server by providing a malicious payload with the Sec-WebSocket-Extensions header.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | ruby-websocket-extensions Ubuntu 18.04.6 LTS (bionic) | 0.1.2-1+deb9u1build0.18.04.1 | [ruby-websocket-extensions 0.1.2-1+deb9u1build0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ruby-websocket-extensions-0.1.2-1-deb9u1build0.18.04.1.md) | Jun 2, 2020 |
| Linux | ruby-websocket-extensions Ubuntu 20.04 LTS (focal) | 0.1.2-1+deb9u1build0.20.04.1 | [ruby-websocket-extensions 0.1.2-1+deb9u1build0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-ruby-websocket-extensions-0.1.2-1-deb9u1build0.20.04.1.md) | Jun 2, 2020 |

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