CVE-2020-15135
HIGHCVE-2020-15135 is a high-severity (CVSS 7.6) Cross-Site Request Forgery (CSRF) vulnerability in save-server. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2020-15135 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
CSRF vulnerability in save-server
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
save-servernpmDescription
save-server (npm package) before version 1.05 is affected by a CSRF vulnerability, as there is no CSRF mitigation (Tokens etc.). The fix introduced in version version 1.05 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 uploading/deleting files and adding redirects. If you are logged in as root, this attack is significantly more severe. They can in addition create, delete and update users. 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. This issue has been patched in version 1.0.7.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | save-server | all versions | 1.0.7 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for save-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update save-server to 1.0.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15135 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2020-15135 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2020-15135. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2020-15135 in your dependencies?
O3 detects CVE-2020-15135 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.