CVE-2020-5280Network attack vector

Unauthenticated file disclosure via improper URI normalization

Published Mar 25, 2020 · Updated Aug 4, 2024

Path traversal in http4s-server allows remote attackers to read files outside configured roots through crafted request paths. FileService and ResourceService resolve improperly normalized ../, //, or prefix-matched paths beyond their configured filesystem or classpath roots, while WebjarService also mishandles encoded segments. Any application using these static-content services is exposed when untrusted clients can reach the mounted route, enabling unauthenticated disclosure of local files or classpath resources.

CVSS severity7.6
High
EPSS probability6.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in http4s-server allows remote attackers to read files outside configured roots through crafted request paths. FileService and ResourceService resolve improperly normalized ../, //, or prefix-matched paths beyond their configured filesystem or classpath roots, while WebjarService also mishandles encoded segments. Any application using these static-content services is exposed when untrusted clients can reach the mounted route, enabling unauthenticated disclosure of local files or classpath resources.

The record

CVE
CVE-2020-5280
Published
Mar 25, 2020
Updated
Aug 4, 2024
Vendor
http4s
Product
http4s
Classifications
CWE-23, CWE-22, T1005, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 25, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.18.26
  2. Affected versionversion=>= 0.19.0, < 0.20.20
  3. Affected versionversion=>= 0.21.0, < 0.21.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

http4s · http4sversion=< 0.18.26; version=>= 0.19.0, < 0.20.20; version=>= 0.21.0, < 0.21.2

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
7.6GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-23Relative Path Traversal
CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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