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No exploitation reportedFix available

CVE-2021-24105

No exploitation reported by the sources we read.

  • Published2021-02-25

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

<p>Depending on configuration of various package managers it is possible for an attacker to insert a malicious package into a package manager's repository which can be retrieved and used during development, build, and release processes. This insertion could lead to remote code execution. We believe this vulnerability affects multiple package managers across multiple languages, including but not limited to: Python/pip, .NET/NuGet, Java/Maven, JavaScript/npm.</p> <p><strong>Attack scenarios</strong></p> <p>An attacker could take advantage of this ecosystem-wide issue to cause harm in a variety of ways. The original attack scenarios were discovered by Alex Birsan and are detailed in their whitepaper, <a href="https://medium.com/@alex.birsan/dependency-confusion-4a5d60fec610">Dependency Confusion: How I Hacked Into Apple, Microsoft and Dozens of Other Companies</a>.</p> <ul> <li><p>With basic knowledge of the target ecosystems, an attacker could create an empty shell for a package and insert malicious code in the install scripts, give it a high version, and publish it to the public repository. Vulnerable victim machines will download the higher version of the package between the public and private repositories and attempt to install it. Due to code incompatibility it will probably error out upon import or upon compilation, making it easier to detect; however the attacker would have gained code execution by that point.</p> </li> <li><p>An advanced attacker with some inside knowledge of the target could take a copy of a working package, insert the malicious code (in the package itself or in the install), and then publish it to a public repository. The package will likely install and import correctly, granting the attacker an initial foothold and persistence.</p> </li> </ul> <p>These two methods could affect target organizations at any of these various levels:</p> <ul> <li>Developer machines</li> <li>An entire team if the configuration to import the malicious package is uploaded to a code repository</li> <li>Continuous integration pipelines if they pull the malicious packages during the build, test, and/or deploy stages</li> <li>Customers, download servers, production services if the malicious code has not been detected</li> </ul> <p>This remote code execution vulnerability can only be addressed by reconfiguring installation tools and workflows, and not by correcting anything in the package repositories themselves. See the <strong>FAQ</strong> section of this CVE for configuration guidance.</p>

Timeline

dates in UTC
  1. 2021-02-2523:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-24105?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-24105?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Microsoft package manager configurations
BranchAffectedFixed in
—all versionsno fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CNACVSS 3.18.4read 2026-10-23
  • NVDCVSS 3.17.8read 2026-10-23
  • NVDCVSS 2.06.8read 2026-10-23
  • FIRST EPSSEPSS score2.4 %2026-10-22

Technical details

CVSS v3 Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published
2021-02-25
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2021-24105?

<p>Depending on configuration of various package managers it is possible for an attacker to insert a malicious package into a package manager's repository which can be retrieved and used during development, build, and release processes. This insertion could lead to remote code execution. We believe this vulnerability affects multiple package managers across multiple languages, including but not limited to: Python/pip, .NET/NuGet, Java/Maven, JavaScript/npm.</p> <p><strong>Attack scenarios</strong></p> <p>An attacker could take advantage of this ecosystem-wide issue to cause harm in a variety of ways. The original attack scenarios were discovered by Alex Birsan and are detailed in their whitepaper, <a href="https://medium.com/@alex.birsan/dependency-confusion-4a5d60fec610">Dependency Confusion: How I Hacked Into Apple, Microsoft and Dozens of Other Companies</a>.</p> <ul> <li><p>With basic knowledge of the target ecosystems, an attacker could create an empty shell for a package and insert malicious code in the install scripts, give it a high version, and publish it to the public repository. Vulnerable victim machines will download the higher version of the package between the public and private repositories and attempt to install it. Due to code incompatibility it will probably error out upon import or upon compilation, making it easier to detect; however the attacker would have gained code execution by that point.</p> </li> <li><p>An advanced attacker with some inside knowledge of the target could take a copy of a working package, insert the malicious code (in the package itself or in the install), and then publish it to a public repository. The package will likely install and import correctly, granting the attacker an initial foothold and persistence.</p> </li> </ul> <p>These two methods could affect target organizations at any of these various levels:</p> <ul> <li>Developer machines</li> <li>An entire team if the configuration to import the malicious package is uploaded to a code repository</li> <li>Continuous integration pipelines if they pull the malicious packages during the build, test, and/or deploy stages</li> <li>Customers, download servers, production services if the malicious code has not been detected</li> </ul> <p>This remote code execution vulnerability can only be addressed by reconfiguring installation tools and workflows, and not by correcting anything in the package repositories themselves. See the <strong>FAQ</strong> section of this CVE for configuration guidance.</p>

Is CVE-2021-24105 actively exploited?

Active exploitation of CVE-2021-24105 has not been confirmed. Its EPSS score was 2.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-24105?

CVE-2021-24105 has a CVSS v3 base score of 7.8 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

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