CVE-2021-23423

Local file disclosure via unconstrained include paths

Published Aug 16, 2021 · Updated Sep 17, 2024

Path traversal in Bikeshed before 3.0.0 allows attackers to disclose arbitrary local-file contents via a crafted source document. FileInputSource.relative joins include, include-code, and include-raw paths to the source directory without ensuring the resolved path remains beneath it. Exploitation requires a trusted process to build an untrusted source file; disclosed data is copied into the resulting HTML without modifying or deleting files.

CVSS severity5.5
Medium
EPSS probability1.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Path traversal in Bikeshed before 3.0.0 allows attackers to disclose arbitrary local-file contents via a crafted source document. FileInputSource.relative joins include, include-code, and include-raw paths to the source directory without ensuring the resolved path remains beneath it. Exploitation requires a trusted process to build an untrusted source file; disclosed data is copied into the resulting HTML without modifying or deleting files.

The record

CVE
CVE-2021-23423
Published
Aug 16, 2021
Updated
Sep 17, 2024
Vendor
Bikeshed Project
Product
Bikeshed
Classifications
CWE-22, T1005
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 16, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <3.0.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Bikeshed Project · Bikeshedversion=unspecified <3.0.0

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.5SnykCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo