Path Traversal in Onlyoffice Document Server
CVE-2021-25833
A file extension handling issue was found in [server] module of ONLYOFFICE DocumentServer v4.2.0.71-v5.6.0.21. The file extension is controlled by an attacker through the request data and leads to arbitrary file overwriting. Using this vulnerability, a remote attacker can obtain remote code execution on DocumentServer.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.435 (98.7th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 99th percentile — 98.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.435 · newest: 0.435 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/ONLYOFFICE/DocumentServer (Product, Vendor Advisory)
- github.com/ONLYOFFICE/server (Product)
- github.com/ONLYOFFICE/server/blob/v5.6.0.21/DocService/sources/converterservice… (Third Party Advisory)
- github.com/ONLYOFFICE/server/blob/v5.6.0.21/FileConverter/sources/converter.js (Third Party Advisory)
- github.com/ONLYOFFICE/server/blob/v5.6.0.21/FileConverter/sources/converter.js (Third Party Advisory)
- github.com/merrychap/poc_exploits/tree/master/ONLYOFFICE/CVE-2021-25833 (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-25833?
- CVE-2021-25833 is a critical-severity vulnerability in Onlyoffice Document Server, classified under Path Traversal. CVSS score: 9.8/10. Published 2021-03-01.
- How severe is CVE-2021-25833?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2021-25833 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.