Server-side rendering vulnerabilities could allow attackers to steal authorization headers or perpetrate phishing and SEO hacking. Credit: Bastian Herrmann / Shutterstock The Angular team from Google has announced the release of two security updates to the Angular web framework, both pertaining to SSR (server-side rendering) vulnerabilities. Developers are advised to update SSR applications as soon as possible. Patching can help users avoid the theft of authorization headers as well as phishing scams. A bulletin on the issues was published February 28. One of the vulnerabilities, labeled as critical, pertains to SSRF (server-side request forgery) and header injection. The patched version can be found here. The second vulnerability, labeled as moderate, pertains to an open redirect via the X-Forwarded-Prefix header. That patch can be found here. The SSRF vulnerability found in the Angular SSR request handling pipeline exists because Angular’s internal URL reconstruction logic directly trusts and consumes user-controlled HTTP headers, specifically the host and X-Forwarded-* family, to determine the application’s base origin without validation of the destination domain. This vulnerability manifests through implicit relative URL resolution, explicit manual construction, and confidentiality breach, the Angular team said. When exploited successfully, this SSRF vulnerability allows for arbitrary internal request steering. This can lead to the stealing sensitive Authorizationheaders or session cookies by redirecting them to an attacker’s server. Attackers also can access and transmit data from internal services, databases, or cloud metadata endpoints not exposed to the public internet. Also, attackers could access sensitive information processed within the application’s server-side context. The open redirect vulnerability, meanwhile, exists in the internal URL processing logic in Angular SSR. This vulnerability allows attackers to conduct large-scale phishing and SEO hijacking, the Angular team said. The team recommends updating SSR applications to the latest patch version as soon as possible. If an app does not deploy SSR to production, there is no immediate need to update, they said. Developers on an unsupported version of Angular or unable to update quickly are advised to avoid using req.headers for URL construction. Instead, they should use trusted variables for base API paths. Another workaround is implementing a middleware in the server.ts to enforce numeric ports and validated hostnames. Application SecurityDevelopment ApproachesJavaScriptProgramming LanguagesSecuritySoftware DevelopmentTypeScriptWeb Development