Summary
rails-ujs vulnerable to DOM Based Cross-site Scripting contenteditable HTML Elements
NOTE: rails-ujs is part of Rails/actionview since 5.1.0.
There is a potential DOM based cross-site scripting issue in rails-ujs
which leverages the Clipboard API to target HTML elements that are
assigned the contenteditable attribute. This has the potential to
occur when pasting malicious HTML content from the clipboard that
includes a data-method, data-remote or data-disable-with attribute.
This vulnerability has been assigned the CVE identifier CVE-2023-23913.
Not affected: < 5.1.0
Versions Affected: >= 5.1.0
Fixed Versions: 6.1.7.3, 7.0.4.3
Impact
If the specified malicious HTML clipboard content is provided to a
contenteditable element, this could result in the arbitrary execution
of javascript on the origin in question.
Releases
The FIXED releases are available at the normal locations.
Workarounds
We recommend that all users upgrade to one of the FIXED versions.
In the meantime, users can attempt to mitigate this vulnerability
by removing the contenteditable attribute from elements in pages
that rails-ujs will interact with.
Patches
To aid users who aren’t able to upgrade immediately we have provided
patches for the two supported release series. They are in git-am
format and consist of a single changeset.
- rails-ujs-data-method-contenteditable-6-1.patch - Patch for 6.1 series
- rails-ujs-data-method-contenteditable-7-0.patch - Patch for 7.0 series
Please note that only the 7.0.Z and 6.1.Z series are
supported at present, and 6.0.Z for severe vulnerabilities.
Users of earlier unsupported releases are advised to upgrade as
soon as possible as we cannot guarantee the continued availability
of security fixes for unsupported releases.
Credits
We would like to thank ryotak 15 for reporting this!
- rails-ujs-data-method-contenteditable-6-1.patch (8.5 KB)
- rails-ujs-data-method-contenteditable-7-0.patch (8.5 KB)
- rails-ujs-data-method-contenteditable-main.patch (8.9 KB)
Impact
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-2023-23913 has a CVSS score of 6.3 (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 (6.1.7.3, 7.0.4.3); 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.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
actionview to 6.1.7.3 or later; actionview to 7.0.4.3 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2023-23913? CVE-2023-23913 is a medium-severity cross-site scripting (XSS) vulnerability in actionview (rubygems), affecting versions >= 5.1.0, < 6.1.7.3. It is fixed in 6.1.7.3, 7.0.4.3. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2023-23913? CVE-2023-23913 has a CVSS score of 6.3 (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 actionview are affected by CVE-2023-23913? actionview (rubygems) versions >= 5.1.0, < 6.1.7.3 is affected.
- Is there a fix for CVE-2023-23913? Yes. CVE-2023-23913 is fixed in 6.1.7.3, 7.0.4.3. Upgrade to this version or later.
- Is CVE-2023-23913 exploitable, and should I be worried? Whether CVE-2023-23913 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-2023-23913 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-2023-23913?
- Upgrade
actionviewto 6.1.7.3 or later - Upgrade
actionviewto 7.0.4.3 or later
- Upgrade