Security readout for executives and security teams
Plain-English summary
CVE-2021-39160 affects nbgitpuller, a Jupyter extension used to pull Git repositories into user environments. A maliciously crafted link could execute arbitrary code in the user's environment after the user visits it. The vendor fixed this in version 0.10.2 and states no workaround exists for users who cannot upgrade.
Executive priority
Treat this as urgent for Jupyter-based education, research, and data science environments. The issue can lead to code execution in user workspaces, but available evidence requires user interaction and does not show confirmed active exploitation.
Technical view
nbgitpuller versions 0.9.0 through before 0.10.2 had unsanitized input leading to code injection, classified as CWE-94. The CVSS 3.1 score is 9.6 with network attack vector, low complexity, no privileges required, user interaction required, changed scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely in JupyterHub or Jupyter server deployments using nbgitpuller versions >=0.9.0 and <0.10.2, especially where users can receive and open repository pull links.
Exploitation context
The provided sources describe exploitation through maliciously crafted links requiring user interaction. The source bundle does not cite active exploitation, and KEV status is false, so active exploitation should not be assumed.
Researcher notes
Focus validation on package version and deployment context. The key boundary is whether users can be induced to visit crafted nbgitpuller links in environments running affected versions. The public sources identify the fix but do not provide a workaround or exploitation-in-the-wild evidence.
Mitigation direction
- Upgrade nbgitpuller to version 0.10.2 or later.
- Inventory Jupyter environments for affected nbgitpuller versions.
- Do not rely on a workaround; vendor sources state none exists.
- If upgrade is blocked, consult current vendor guidance and document residual risk.
- Warn users against opening untrusted nbgitpuller links until remediation is complete.
Validation and detection
- Confirm whether nbgitpuller is installed in Jupyter environments.
- Verify installed nbgitpuller versions are 0.10.2 or later.
- Review base images and dependency files for pinned affected versions.
- Check managed notebook platforms and shared hubs for inherited vulnerable installations.
- Confirm change records show the fixed package deployed to user environments.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-94: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-39160 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H2.86Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.6CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/jupyterhub/nbgitpuller/security/advisories/GHSA-mq5p-2mcr-m52jCVE reference · x_refsource_CONFIRM
- https://github.com/jupyterhub/nbgitpuller/commit/07690644f29a566011dd0d7ba14cae3eb0490481CVE reference · x_refsource_MISC
- https://github.com/jupyterhub/nbgitpuller/blob/main/CHANGELOG.md#0102---2021-08-25CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Control of Generation of Code ('Code Injection')
Improper Control of Generation of Code ('Code Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.