CVE-2022-29183 is a reflected cross-site scripting (XSS) vulnerability affecting GoCD, a continuous delivery server widely used for automating software deployment pipelines. The vulnerability exists in GoCD versions from 20.2.0 up to but not including 21.4.0. Specifically, the flaw arises from improper neutralization of input during web page generation within the pipeline comparison function's error handling mechanism. When an error occurs in this function, it improperly renders user-supplied input as HTML in the response page without adequate sanitization or encoding. This allows an attacker to craft malicious URLs that, when visited by an authenticated user, execute arbitrary JavaScript in the context of the victim's browser session. Exploiting this vulnerability could enable attackers to hijack user sessions, steal sensitive information such as authentication tokens, or perform actions on behalf of the victim within the GoCD environment. The vulnerability does not require prior authentication to trigger the reflected XSS, but the impact is primarily on authenticated users who access the maliciously crafted URL. The issue was fixed in GoCD version 21.4.0. As an interim mitigation, organizations can block access to the vulnerable endpoint path (/go/compare/.*) using reverse proxies or web application firewalls to prevent exploitation of the pipeline comparison function. No known exploits have been reported in the wild to date.

For European organizations utilizing GoCD for continuous integration and delivery, this vulnerability poses a risk of session hijacking and unauthorized actions within their software deployment pipelines. Successful exploitation could lead to unauthorized code deployments, leakage of sensitive pipeline configuration data, or disruption of automated delivery workflows. This could impact the integrity and availability of software delivery processes, potentially causing delays or introducing malicious code into production environments. Confidentiality is also at risk if attackers steal session cookies or other sensitive data via the XSS attack. Given the critical role of CI/CD pipelines in modern software development, exploitation could have cascading effects on business operations, compliance, and customer trust. Organizations in sectors with stringent regulatory requirements (e.g., finance, healthcare, critical infrastructure) may face additional compliance risks if such vulnerabilities are exploited.

Beyond applying the official GoCD patch by upgrading to version 21.4.0 or later, European organizations should implement the following specific mitigations: 1) Configure reverse proxies or web application firewalls to block or filter requests targeting the /go/compare/.* endpoint to prevent access to the vulnerable pipeline comparison function. 2) Implement Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of potential XSS payloads. 3) Conduct regular security awareness training for developers and DevOps teams to recognize and avoid unsafe URL handling practices. 4) Monitor web server and application logs for unusual requests to the vulnerable endpoint or signs of attempted exploitation. 5) Employ multi-factor authentication (MFA) for GoCD access to reduce the risk of session hijacking leading to unauthorized actions. 6) Review and harden GoCD user permissions to limit the scope of what an attacker could do if an XSS attack succeeds. 7) Integrate automated security scanning into CI/CD pipelines to detect similar input validation issues proactively.