Password-hash weakening via Perl rand salt generation
Published May 8, 2026 · Updated May 8, 2026
Weak salt generation in Ron Savage Crypt::PasswdMD5 1.42 and earlier allows attackers to predict salts in automatically generated MD5 password hashes. The random_md5_salt routine selects every salt character with int(rand(64)), using Perl's predictable general-purpose PRNG for cryptographic material. Exposure requires a caller to omit the salt passed to apache_md5_crypt or unix_md5_crypt; the module weakens resulting hashes but does not expose them.
Summary
What happened
Weak salt generation in Ron Savage Crypt::PasswdMD5 1.42 and earlier allows attackers to predict salts in automatically generated MD5 password hashes. The random_md5_salt routine selects every salt character with int(rand(64)), using Perl's predictable general-purpose PRNG for cryptographic material. Exposure requires a caller to omit the salt passed to apache_md5_crypt or unix_md5_crypt; the module weakens resulting hashes but does not expose them.
The record
- CVE
- CVE-2026-6659
- Published
- May 8, 2026
- Updated
- May 8, 2026
- Vendor
- Ron Savage
- Product
- Crypt::PasswdMD5
- Classifications
- CWE-338
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- May 8, 2026CVE publishedPublication date reported by the CVE source.
- May 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <=1.42
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Technologies
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