Summary
Subdomain Takeover in Interactsh server
A domain configured with interactsh server was vulnerable to subdomain takeover for specfic subdomain, i.e app, Interactsh server before < 1.0.0 used to create cname entries for app pointing to projectdiscovery.github.io as default which intended to used for hosting interactsh web client using GitHub pages. It turns out to be a security issue with a self-hosted interactsh server in which the user may not have configured a web client but still have a cname entry pointing to GitHub pages, making them vulnerable to subdomain takeover.
This issue was initially reported to us as a subdomain takeover for one of our domains that runs interactsh server by Melih at [email protected], and after conducting an internal investigation, we determined that it was an issue with the default config of interactsh server affecting all the server running self-hosted instance of interactsh, as a result - cname entry has been removed in the latest release.
References
https://github.com/projectdiscovery/interactsh/issues/136
For more information
If you have any questions or comments about this advisory:
- Email us at [email protected]
Impact
This allows one to host / run arbitrary client side code (XSS) in a user's browser when browsing the vulnerable subdomain, for more details on the impact, please read this detailed blogpost from Detectify.
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-2023-36474 has a CVSS score of 6.1 (Medium). 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 (1.0.0); 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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Update to Interactsh server v1.0.0 with go install -v github.com/projectdiscovery/interactsh/cmd/interactsh-server@latest
Frequently Asked Questions
- What is CVE-2023-36474? CVE-2023-36474 is a medium-severity cross-site scripting (XSS) vulnerability in github.com/projectdiscovery/interactsh (go), affecting versions < 1.0.0. It is fixed in 1.0.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2023-36474? CVE-2023-36474 has a CVSS score of 6.1 (Medium). 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 github.com/projectdiscovery/interactsh are affected by CVE-2023-36474? github.com/projectdiscovery/interactsh (go) versions < 1.0.0 is affected.
- Is there a fix for CVE-2023-36474? Yes. CVE-2023-36474 is fixed in 1.0.0. Upgrade to this version or later.
- Is CVE-2023-36474 exploitable, and should I be worried? Whether CVE-2023-36474 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-2023-36474 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-2023-36474? Upgrade
github.com/projectdiscovery/interactshto 1.0.0 or later.