Authenticated code execution via configuration newline injection
Published Aug 27, 2021 · Updated Aug 4, 2024
CRLF injection in Cachet before 2.5.1 allows remote authenticated users to execute arbitrary code through configuration editing. UpdateConfigCommandHandler replaces existing .env entries with unvalidated values, so embedded newlines add attacker-chosen directives and can redirect serialized Laravel sessions to an attacker-controlled Redis server for PHP object injection. Any basic user account can reach the affected mail-settings path, and successful exploitation runs code on the Cachet host.
Summary
What happened
CRLF injection in Cachet before 2.5.1 allows remote authenticated users to execute arbitrary code through configuration editing. UpdateConfigCommandHandler replaces existing .env entries with unvalidated values, so embedded newlines add attacker-chosen directives and can redirect serialized Laravel sessions to an attacker-controlled Redis server for PHP object injection. Any basic user account can reach the affected mail-settings path, and successful exploitation runs code on the Cachet host.
The record
- CVE
- CVE-2021-39172
- Published
- Aug 27, 2021
- Updated
- Aug 4, 2024
- Vendor
- CachetHQ
- Product
- Cachet
- Classifications
- CWE-93, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 27, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 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=< 2.5.1
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
- Cachet Laravel configuration-injection demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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