CVE-2020-8161

A directory traversal vulnerability exists in rack < 2.2.0 that allows an attacker perform directory traversal vulnerability in the Rack::Directory app that is bundled with Rack which could result in information disclosure.

Published: 2020-07-02 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-8161 is rated High Risk (67.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.59%). EPSS rose +2.69% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-8161

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.91% 3.59% +2.69%
2 2026-03-10 0.84% 0.91% +0.07%
3 2026-03-04 — 0.84% —

Full EPSS history (42 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-8161

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 4.0 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-8161

GitHub Security Advisory for CVE-2020-8161

GHSA-5f9h-9pjv-v6j7 · Severity: high · Ecosystem: rubygems — Directory traversal in Rack::Directory app bundled with Rack

OS Trackers for CVE-2020-8161

vendor priority summary link
debian not yet assigned CVE-2020-8161 not yet assigned priority: Debian including 1 source packages (ruby-rack), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-8161
redhat medium — https://access.redhat.com/security/cve/CVE-2020-8161
suse medium — https://www.suse.com/security/cve/CVE-2020-8161/
ubuntu low CVE-2020-8161 low priority: Ubuntu including 1 source packages (ruby-rack), 10 status rows across 10 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, trusty, upstream, xenial): released 5, not-affected 4, ignored 1. https://ubuntu.com/security/CVE-2020-8161

Affected software / configurations for CVE-2020-8161

Vendor Product Version Raw CPE
rack_project rack < 2.2.0 cpe:2.3:a:rack_project:rack:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*

References for CVE-2020-8161

URL Tags
https://groups.google.com/g/rubyonrails-security/c/IOO1vNZTzPA Mailing List Patch Third Party Advisory
https://hackerone.com/reports/434404 Permissions Required Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00006.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/01/msg00038.html Mailing List Third Party Advisory
https://usn.ubuntu.com/4561-1/ Third Party Advisory
cvelogic Threat Intelligence