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CVE Record

CVE-2021-34426: Arbitrary command execution in Keybase Client for Windows

A vulnerability was discovered in the Keybase Client for Windows before version 5.6.0 when a user executed the "keybase git lfs-config" command on the command-line. In versions prior to 5.6.0, a malicious actor with write access to a user\'s Git repository could leverage this vulnerability to potentially execute arbitrary Windows commands on a user\'s local system.

MediumCVSS 5.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

On Windows, older Keybase clients could let someone who can write to a user's Git repository run Windows commands on that user's machine if the user runs the affected Keybase Git LFS command. It requires user action and repository write access, so it is not internet-wide remote code execution, but it can affect developer workstations.

Executive priority

Prioritize remediation for developer workstations and teams using Keybase Git. Business urgency is moderate because exploitation requires user action and repository write access, but successful abuse could execute commands on local Windows systems.

Technical view

CVE-2021-34426 affects Keybase Client for Windows before 5.6.0. The public record says the issue is triggered when a user runs "keybase git lfs-config" and a malicious actor has write access to that user's Git repository. The source bundle does not describe the underlying root cause or exploit mechanics.

Likely exposure

Exposure is mainly Windows endpoints running Keybase Client before 5.6.0, especially developer or engineering systems using Keybase Git repositories where another party can write repository content.

Exploitation context

The CVE is not listed as KEV in the provided bundle, and no cited source states active exploitation. Practical exploitation depends on repository write access plus the user running the vulnerable command.

Researcher notes

The available sources provide impact, trigger condition, affected platform, and fixed-version boundary, but not root-cause detail, proof-of-concept status, or indicators of compromise. Treat exploitability claims beyond those facts as unconfirmed.

Mitigation direction

  • Upgrade Keybase Client for Windows to version 5.6.0 or later.
  • Review Zoom or Keybase security guidance for any additional vendor instructions.
  • Restrict write access to repositories used by Keybase Git workflows.
  • Avoid running the affected command against repositories with untrusted writers.

Validation and detection

  • Inventory Windows endpoints with Keybase Client installed.
  • Confirm installed Keybase Client versions are 5.6.0 or later.
  • Identify users or workflows that run Keybase Git LFS configuration.
  • Review repository permissions for untrusted or unnecessary writers.
Prepared
Confidence
medium
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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

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CVE-2021-34426 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.3 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
5.3CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L1.83.4Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

5.3Medium
CVSS 3.1 vector shape for CVE-2021-34426Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Zoom Video Communications IncKeybase Client for WindowsunspecifiedListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.