Account takeover via loose MD5 comparison
Published May 13, 2024 · Updated Nov 4, 2025
Authentication bypass in Cacti before 1.2.27 allows remote attackers to access accounts whose legacy MD5 password hashes resemble numbers. The compat_password_verify function compares attacker-supplied MD5 output to a stored hash with PHP's loose equality operator, coercing 0e-prefixed hashes to zero. Exploitation requires a target account with a legacy numeric-form MD5 hash and grants that account's Cacti privileges.
Summary
What happened
Authentication bypass in Cacti before 1.2.27 allows remote attackers to access accounts whose legacy MD5 password hashes resemble numbers. The compat_password_verify function compares attacker-supplied MD5 output to a stored hash with PHP's loose equality operator, coercing 0e-prefixed hashes to zero. Exploitation requires a target account with a legacy numeric-form MD5 hash and grants that account's Cacti privileges.
The record
- CVE
- CVE-2024-34340
- Published
- May 13, 2024
- Updated
- Nov 4, 2025
- Vendor
- The Cacti Group
- Product
- Cacti
- Classifications
- CWE-287, CWE-697, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 13, 2024CVE publishedPublication date reported by the CVE source.
- Nov 4, 2025Record 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=0 <1.2.27
- Affected versionversion=< 1.2.27
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- Upstream magic-hash authentication bypass proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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