CVE-2020-28337 is a high-severity (CVSS 7.2) Path Traversal vulnerability in microweber/microweber. 3 public exploit references exist, so weaponization risk is real. A fix is available for microweber/microweber — see the affected versions and patch details below.
Zip slip in Microweber
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-28337 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
microweber/microweberReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
A directory traversal issue in the Utils/Unzip module in Microweber through 1.1.20 allows an authenticated attacker to gain remote code execution via the backup restore feature. To exploit the vulnerability, an attacker must have the credentials of an administrative user, upload a maliciously constructed ZIP file with file paths including relative paths (i.e., ../../), move this file into the backup directory, and execute a restore on this file.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | microweber/microweber | all versions | 1.2.3composer require microweber/microweber:^1.2.3 |
Affected Products
microwebermicroweberResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Microweber CMS 1.1.20 - Remote Code Execution (Authenticated)
by sl1nki · May 10, 2021
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for microweber/microweber, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update microweber/microweber to 1.2.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-28337 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2020-28337 in your dependencies?
Find it across Packagist, including transitive dependencies.