What is CVE-2020-15135?

CVE-2020-15135 is a medium-severity cross-site request forgery (CSRF) vulnerability in save-server (npm), affecting versions < 1.0.5. It is fixed in 1.0.7. A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones.

How severe is CVE-2020-15135?

CVE-2020-15135 has a CVSS score of 6.7 (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 save-server are affected by CVE-2020-15135?

save-server (npm) versions < 1.0.5 is affected.

Is there a fix for CVE-2020-15135?

Yes. CVE-2020-15135 is fixed in 1.0.7. Upgrade to this version or later.

Is CVE-2020-15135 exploitable, and should I be worried?

Whether CVE-2020-15135 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.

What actually determines whether CVE-2020-15135 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-2020-15135?

Upgrade save-server to 1.0.7 or later.

CVE-2020-15135 in save-server

Q: How severe is CVE-2020-15135?

CVE-2020-15135 has a CVSS score of 6.7 (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.

Q: Which versions of save-server are affected by CVE-2020-15135?

save-server (npm) versions < 1.0.5 is affected.

Q: Is there a fix for CVE-2020-15135?

Yes. CVE-2020-15135 is fixed in 1.0.7. Upgrade to this version or later.

Q: Is CVE-2020-15135 exploitable, and should I be worried?

Whether CVE-2020-15135 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.

Q: What actually determines whether CVE-2020-15135 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.

Q: How do I fix CVE-2020-15135?

Upgrade save-server to 1.0.7 or later.

Summary

CSRF vulnerability in save-server

If you are logged in as root, this attack is significantly more severe. They can (in addition to the above):

Create users
Delete users
Update users (change password)

If they updated the password of a user, that user's files would then be available. If the root password is updated, all files would be visible if they logged in with the new password.

Note that due to the same origin policy malicious actors cannot view the gallery or the response of any of the methods, nor be sure they succeeded.

Workarounds

None. You should upgrade.

References

What is CSRF: https://owasp.org/www-community/attacks/csrf
Fix type: https://medium.com/cross-site-request-forgery-csrf/double-submit-cookie-pattern-65bb71d80d9f

For more information

If you have any questions or comments about this advisory:

Open an issue in Save-server
Email us at [email protected]
Join our discord (preferred): Invite

Impact

Versions prior to version v1.05 are affected by a CSRF vulnerability, as there is no CSRF mitigation (Tokens etc.). The fix introduced in version v1.05 unintentionally breaks uploading so version v1.0.7 is the fixed version.

This is patched by implementing Double submit.

The CSRF attack would require you to navigate to a malicious site while you have an active session with Save-Server (Session key stored in cookies). The malicious user would then be able to perform some actions, including:

Upload file
Delete file
Add redirect

A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones. Typical impact: state-changing actions performed as the victim without their consent.

CVE-2020-15135 has a CVSS score of 6.7 (Medium). The vector is network-reachable, low 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 (1.0.7); upgrading removes the vulnerable code path.

Affected versions

save-server (< 1.0.5)

Security releases

save-server → 1.0.7 (npm)

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 environment New to Kodem? Get a demo →

Remediation advice

This issue has been patched. Update to version v1.0.7 or above to benefit from this fix.

Frequently Asked Questions

What is CVE-2020-15135? CVE-2020-15135 is a medium-severity cross-site request forgery (CSRF) vulnerability in save-server (npm), affecting versions < 1.0.5. It is fixed in 1.0.7. A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones.
How severe is CVE-2020-15135? CVE-2020-15135 has a CVSS score of 6.7 (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 save-server are affected by CVE-2020-15135? save-server (npm) versions < 1.0.5 is affected.
Is there a fix for CVE-2020-15135? Yes. CVE-2020-15135 is fixed in 1.0.7. Upgrade to this version or later.
Is CVE-2020-15135 exploitable, and should I be worried? Whether CVE-2020-15135 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-2020-15135 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-2020-15135? Upgrade save-server to 1.0.7 or later.