CVE intelligence and bounded remediation
CVE-2021-34422 — Keybase Keybase security vulnerability
The Keybase Client for Windows before version 5.7.0 contains a path traversal vulnerability when checking the name of a file uploaded to a team folder. A malicious user could upload a file to a shared folder with a specially crafted file name which could allow a user to execute an application which was not intended on their host machine. If a malicious user leveraged this issue with the public folder sharing feature of the Keybase client, this could lead to remote code execution.
- Severity
- Critical
- CVSS
- 9 (3.1)
- Published
- 2021-11-11
- CISA KEV
- Not currently listed
- Ecosystem
- windows/system
- Weaknesses
- CWE-22
Affected products
- keybase / keybase
Matched remediation archetype
Path traversal, unsafe upload, and file handling
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
- Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
- Review canonicalization and containment checks across supported operating systems and storage backends.
Remediate safely
- Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
- Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
- Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.
Authoritative sources
Complete CVE record and remediation plan
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