Arbitrary file upload in Expressionengine
CVE-2020-13443
ExpressionEngine before 5.3.2 allows remote attackers to upload and execute arbitrary code in a .php%20 file via Compose Msg, Add attachment, and Save As Draft actions. A user with low privileges (member) is able to upload this. It is possible to bypass the MIME type check and file-extension check while uploading new files. Short aliases are not used for an attachment; instead, direct access is allowed to the uploaded files. It is possible to upload PHP only if one has member access, or registration/forum is enabled and one can create a member with the default group id of 5. To exploit this, one must to be able to send and compose messages (at least).
Vulnerability class: Unrestricted File Upload
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.041 (90.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 90.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.041 · newest: 0.041 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- expressionengine.com/blog (Vendor Advisory)
- gist.github.com/mariuszpoplwski/51604d8a6d7d78fffdf590c25e844e09 (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-13443?
- CVE-2020-13443 is a high-severity vulnerability in Expressionengine, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 8.8/10. Published 2020-06-24.
- How severe is CVE-2020-13443?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2020-13443 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.