CVE intelligence and bounded remediation

CVE-2021-24105 — Microsoft Package Manager Configurations security vulnerability

High CVSS 8.4

<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 publi…

Severity
High
CVSS
8.4 (3.1)
Published
2021-02-25
CISA KEV
Not currently listed
Ecosystem
windows/system

Affected products

  • microsoft / package_manager_configurations

Matched remediation archetype

Command, code, expression, and template injection

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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