CVE-2021-48011 json
Servor 1.0.0 through 4.0.2 Unauthenticated Path Traversal via URL-Encoded Dot Segments
published 2026-10-12 27 d ago modified 2026-10-16 23 d ago also EUVD-2021-34884
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 46%
- public exploits
- 0
- none known
Summary
Servor 1.0.0 through 4.0.2 contains a path traversal vulnerability that allows unauthenticated remote attackers to escape the served root by sending URL-encoded dot segments. Attackers can send %2e%2e/ sequences, which decodeURI() decodes before path.join() in serveStaticFile and serveDirectoryListing, to read arbitrary files and list directories outside the root.
Patch / fix
- github.com/lukejacksonn/servor@ec7d824 commit
- github.com/lukejacksonn/servor#70 pull request
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 27 d ago
Exploit prediction
0.56% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- lukejacksonn servor
Classification
- Weakness
-
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory
References
-
github.com
/lukejacksonn/servor/pull/70
issue-tracking, patch
-
github.com
/lukejacksonn/servor/commit/ec7d824ea6903c0fb97a452045bbb8335198cbab
patch
-
github.com
/lukejacksonn/servor
product
-
vulncheck.com
/advisories/servor-1.0.0-through-4.0.2-unauthenticated-path-traversal-via-url-encoded-dot-segments
third-party-advisory
Sources
- CVE List CVE-2021-48011
- NVD CVE-2021-48011
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