A security feature bypass vulnerability exists in the PowerShellGet V2 module. An attacker who successfully exploited this vulnerability could bypass WDAC (Windows Defender Application Control) policy and execute arbitrary code on a policy locked-down machine.
An attacker must have administrator privileges to create a configuration that includes installing PowerShellGet V2 module onto a machine from the PowerShell Gallery. The WDAC policy must be configured to allow the module to run. After this is done, PowerShell script can be injected and run fully trusted, allowing the attacker arbitrary code execution on the machine.
The update addresses the vulnerability by changing how URLs are processed.
## Which versions are affected by CVE-2020-16886? It affects 1 product. Products: Microsoft Powershellget. ## How do I fix CVE-2020-16886? No fix has been published for CVE-2020-16886 yet. Limit exposure of the affected software until one is available. ## Is CVE-2020-16886 being exploited? There is no known exploitation of CVE-2020-16886 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2020-16886 and fix it if it is affected. What it is: CVE-2020-16886 is a medium-severity vulnerability in Microsoft PowerShellGet 2.2.5, published on 16 Oct 2020. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2020-16886 in the wild and no public exploit code. Affected product: Microsoft PowerShellGet 2.2.5. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2020-16886/ (Markdown: https://insights.sbomify.com/CVE-2020-16886/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-16886 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-16886 - OSV: https://osv.dev/vulnerability/CVE-2020-16886 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-16886/ Summaries are generated and may contain mistakes; the official description above is the record.