SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2021-48011

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.

HIGH 8.7EPSS 0.56%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.56%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 4.0
8.7 HIGHCVSS: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/M
EPSS
0.56% probability · 46th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-22
Source
disclosure@vulncheck.com
EPSS trend
0%3%5%13 October 2026: 0.56%26 October 2026: 0.56%13 October 202626 October 2026

EPSS moved from 0.6% on 13 October 2026 to 0.6% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.