SYSTEM code execution via insecure updater permissions
Published Aug 17, 2021 · Updated Aug 3, 2024
Local privilege escalation in Yandex Browser for Windows before 21.9.0.390 allows local users to execute arbitrary code as SYSTEM. During the browser update process, an update directory uses insecure permissions, allowing a low-privileged user to manipulate files later handled with SYSTEM rights. Exploitation requires local low-privileged access and a triggered update; successful file replacement yields full operating-system control.
Summary
What happened
Local privilege escalation in Yandex Browser for Windows before 21.9.0.390 allows local users to execute arbitrary code as SYSTEM. During the browser update process, an update directory uses insecure permissions, allowing a low-privileged user to manipulate files later handled with SYSTEM rights. Exploitation requires local low-privileged access and a triggered update; successful file replacement yields full operating-system control.
The record
- CVE
- CVE-2021-25263
- Published
- Aug 17, 2021
- Updated
- Aug 3, 2024
- Vendor
- Yandex
- Product
- Yandex Browser
- Classifications
- CWE-732, T1574.005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 17, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=All versions prior to version 21.9.0.390
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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