CVE-2021-24105 — Package Managers Configurations Remote Code Execution Vulnerability
<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>
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 2.4% (30-day exploitation probability)+13
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — portal.msrc.microsoft.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Microsoft Package Manager Configurations).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Microsoft | Package Manager Configurations | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Microsoft | Package Manager Configurations | version N/A | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.4 | CVSS 3.1 | High | 2.5 | 5.9 | secure@microsoft.com via NIST National Vulnerability Database |
| 8.4 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 8.4 | CVSS 3.1 | High | — | — | microsoft via CVE Program (cve.org) e CISA ADP |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 6.8 | CVSS 2.0 | Medium | 8.6 | 6.4 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: secure@microsoft.com) EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 2.37%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · microsoft/package manager configurations
- Record published
- Fix documented
- Affected products added · microsoft/package manager configurations
- CVSS changed · 8.4
- Source status changed · → Modified
- Record created in this database
- 2021
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 13, 2026 – Oct 13, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2020-36327 Dependency Confusion in Bundler Apr 29, 2021
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2021-24105 is "Package Managers Configurations Remote Code Execution Vulnerability", rated High. It affects Package Manager Configurations (Microsoft); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.4 describes technical severity. EPSS 2.37% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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