Angular: URL Parser Differential in @angular/platform-server leading to SSRF Allowlist Bypass
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 22.0.0-rc.2, 21.2.15, 20.3.22, 19.2.23
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 22.0.0-rc.2, 21.2.15, 20.3.22, and 19.2.23, an issue in the @angular/platform-server package allows remote attackers to bypass host allowlist constraints and direct server-side outgoing requests to arbitrary external endpoints. This occurs due to a parser differential between the strict WHATWG URL parser used for allowlist validation and the lenient Domino URL parser used to initialize the server emulated DOM. When a server-side request contains a malformed URL with a double port structure (e.g., http://evil.com:80:80/path), Node's strict URL.canParse(url) logic returns false and skips host check validation entirely. However, the same malformed URL is later accepted and parsed leniently by Domino's internal parser, which resolves the origin to http://evil.com:80. The Angular SSR HTTP request interceptor (relativeUrlsTransformerInterceptorFn) then resolves all relative backend HTTP requests against this adopted origin, executing the SSRF attack. This vulnerability is fixed in 22.0.0-rc.2, 21.2.15, 20.3.22, and 19.2.23.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- angular angular
From 22.0.0-next.0 · fixed in 22.0.0-rc.2; From 21.0.0-next.0 · fixed in 21.2.15; From 20.0.0-next.0 · fixed in 20.3.22; From 19.0.0-next.0 · fixed in 19.2.23; through 18.2.14
- @angular/platform-servernpm
From 22.0.0-next.0 · fixed in 22.0.0-rc.2
- @angular/platform-servernpm
From 20.0.0-next.0 · fixed in 20.3.22
- @angular/platform-servernpm
From 19.0.0-next.0 · fixed in 19.2.23
- @angular/platform-servernpm
through 18.2.14
- @angular/platform-servernpm
From 21.0.0-next.0 · fixed in 21.2.15