Summary
kiwitcms vulnerable to stored cross-site scripting via unrestricted file upload
Workarounds
If serving Kiwi TCMS behind a reverse proxy make sure that additional header values are still passed to the client browser. If they aren't redefine them inside the proxy configuration. See etc/nginx.conf#L66-L68 and etc/nginx.conf#L87
References
Disclosed by M Nadeem Qazi.
Impact
Kiwi TCMS allows users to upload attachments to test plans, test cases, etc. Earlier versions of Kiwi TCMS had introduced upload validators in order to prevent potentially dangerous files from being uploaded and Content-Security-Policy definition to prevent cross-site-scripting attacks.
The upload validation checks were not 100% robust which left the possibility to circumvent them and upload a potentially dangerous file which allows execution of arbitrary JavaScript in the browser. Additionally we've discovered that Nginx's proxy_pass directive will strip some headers negating protections built into Kiwi TCMS when served behind a reverse proxy.
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
CVE-2023-33977 has a CVSS score of 8.1 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (12.4); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
- Improved file upload validation code
- Updated Nginx reverse proxy configuration for ***.tenant.kiwitcms.org**
Frequently Asked Questions
- What is CVE-2023-33977? CVE-2023-33977 is a high-severity cross-site scripting (XSS) vulnerability in kiwitcms (pip), affecting versions <= 12.3. It is fixed in 12.4. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2023-33977? CVE-2023-33977 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of kiwitcms are affected by CVE-2023-33977? kiwitcms (pip) versions <= 12.3 is affected.
- Is there a fix for CVE-2023-33977? Yes. CVE-2023-33977 is fixed in 12.4. Upgrade to this version or later.
- Is CVE-2023-33977 exploitable, and should I be worried? Whether CVE-2023-33977 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-33977 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-33977? Upgrade
kiwitcmsto 12.4 or later.