Angular SSR has an Open Redirect via X-Forwarded-Prefix
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 21.2.0-rc.0, 21.1.5, 20.3.17, 19.2.21, 21.2.0-rc.1
- 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: poc
- Automatable: yes
- Technical impact: partial
Summary
The Angular SSR is a server-rise rendering tool for Angular applications. An Open Redirect vulnerability exists in the internal URL processing logic in versions on the 19.x branch prior to 19.2.21, the 20.x branch prior to 20.3.17, and the 21.x branch prior to 21.1.5 and 21.2.0-rc.1. The logic normalizes URL segments by stripping leading slashes; however, it only removes a single leading slash. When an Angular SSR application is deployed behind a proxy that passes the `X-Forwarded-Prefix` header, an attacker can provide a value starting with three slashes. This vulnerability allows attackers to conduct large-scale phishing and SEO hijacking. In order to be vulnerable, the application must use Angular SSR, the application must have routes that perform internal redirects, the infrastructure (Reverse Proxy/CDN) must pass the `X-Forwarded-Prefix` header to the SSR process without sanitization, and the cache must not vary on the `X-Forwarded-Prefix` header. Versions 21.2.0-rc.1, 21.1.5, 20.3.17, and 19.2.21 contain a patch. Until the patch is applied, developers should sanitize the `X-Forwarded-Prefix` header in their`server.ts` before the Angular engine processes the request.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- angular angular-cli
From 21.2.0-next.2 · fixed in 21.2.0-rc.0; From 21.0.0-next.0 · fixed in 21.1.5; From 20.0.0-next.0 · fixed in 20.3.17; From 19.0.0-next.0 · fixed in 19.2.21
- @angular/ssrnpm
From 21.2.0-next.0 · fixed in 21.2.0-rc.1
- @angular/ssrnpm
From 21.0.0-next.0 · fixed in 21.1.5
- @angular/ssrnpm
From 20.0.0-next.0 · fixed in 20.3.17
- @angular/ssrnpm
From 19.0.0-next.0 · fixed in 19.2.21