Account takeover via bcrypt password truncation
Published Jun 24, 2021 · Updated Aug 3, 2024
Weak password enforcement in OpenEMR 5.0.0 through 6.0.0.1 allows remote attackers to take over accounts via crafted long passwords. AuthUtils accepts passwords beyond bcrypt's 72-character input limit, so bcrypt ignores every character after the shared 72-character prefix. An attacker must know a victim's username and first 72 password characters; authentication then succeeds despite a different suffix.
Summary
What happened
Weak password enforcement in OpenEMR 5.0.0 through 6.0.0.1 allows remote attackers to take over accounts via crafted long passwords. AuthUtils accepts passwords beyond bcrypt's 72-character input limit, so bcrypt ignores every character after the shared 72-character prefix. An attacker must know a victim's username and first 72 password characters; authentication then succeeds despite a different suffix.
The record
- CVE
- CVE-2021-25923
- Published
- Jun 24, 2021
- Updated
- Aug 3, 2024
- Vendor
- OpenEMR Foundation
- Product
- OpenEMR
- Classifications
- CWE-521, T1078
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 24, 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=v5.0.0, v5.0.0.5, v5.0.0.6, v5.0.1, v5.0.1.1, v5.0.1.2, v5.0.1.3, v5.0.1.4, v5.0.1.5, v5.0.1.6, v5.0.1.7, v5.0.2, v5.0.2.1, v5.0.2.2, v5.0.2.3, v5.0.2.4, v6.0.0, v6.0.0.1
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.
Public exploit references
- Mend bcrypt-prefix authentication reproductionproof 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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