Описание
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:
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
Ссылки
- https://github.com/faye/websocket-extensions-ruby/security/advisories/GHSA-g6wq-qcwm-j5g2
- https://nvd.nist.gov/vuln/detail/CVE-2020-7663
- https://github.com/faye/websocket-extensions-ruby/commit/aa156a439da681361ed6f53f1a8131892418838b
- https://blog.jcoglan.com/2020/06/02/redos-vulnerability-in-websocket-extensions
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/websocket-extensions/CVE-2020-7663.yml
- https://lists.debian.org/debian-lts-announce/2020/08/msg00031.html
- https://snyk.io/vuln/SNYK-RUBY-WEBSOCKETEXTENSIONS-570830
- https://usn.ubuntu.com/4502-1
Пакеты
websocket-extensions
< 0.1.5
0.1.5
Связанные уязвимости
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.
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.
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.
websocket-extensions ruby module prior to 0.1.5 allows Denial of Servi ...
