CVE intelligence and bounded remediation
CVE-2021-25261 — Yandex Yandex Browser security vulnerability
High
CVSS 7.8
Local privilege vulnerability in Yandex Browser for Windows prior to 22.5.0.862 allows a local, low privileged, attacker to execute arbitary code with the SYSTEM privileges through manipulating symlinks to installation file during Yandex Browser update process.
- Severity
- High
- CVSS
- 7.8 (3.1)
- Published
- 2022-06-15
- CISA KEV
- Not currently listed
- Ecosystem
- windows/system
- Weaknesses
- CWE-59
Affected products
- yandex / yandex_browser
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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