What’s Vulnerable › Vulnerabilities

CVE-2022-4891: Sisimai string.rb to_plain redos

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2023-01-17 · updated 2026-06-17
• Weakness: CWE-1333

Description

A vulnerability has been found in Sisimai up to 4.25.14p11 and classified as problematic. This vulnerability affects the function to_plain of the file lib/sisimai/string.rb. The manipulation leads to inefficient regular expression complexity. The exploit has been disclosed to the public and may be used. Upgrading to version 4.25.14p12 is able to address this issue. The name of the patch is 51fe2e6521c9c02b421b383943dc9e4bbbe65d4e. It is recommended to upgrade the affected component. The identifier of this vulnerability is VDB-218452.

Affected products

• Sisimai: before 4.25.14; 4.25.14, 4.25.14-p1, 4.25.14-p10, 4.25.14-p11, 4.25.14-p3, 4.25.14-p5 (+4) — fixed in 4.25.14

How to fix

Upgrade to a fixed version: Sisimai 4.25.14. Check the vendor advisory for mitigations.

References

• https://gist.githubusercontent.com/gmcabrita/e5dc0332473fc2e3a7a407434c8d21c7/raw/00b12035e5e1b685469f143b94301a50306376ba/example.html
• https://github.com/sisimai/rb-sisimai/commit/51fe2e6521c9c02b421b383943dc9e4bbbe65d4e
• https://github.com/sisimai/rb-sisimai/pull/244
• https://github.com/sisimai/rb-sisimai/releases/tag/v4.25.14p12
• https://vuldb.com/?ctiid.218452
• https://vuldb.com/?id.218452
• https://gist.githubusercontent.com/gmcabrita/e5dc0332473fc2e3a7a407434c8d21c7/raw/00b12035e5e1b685469f143b94301a50306376ba/example.html
• https://github.com/sisimai/rb-sisimai/commit/51fe2e6521c9c02b421b383943dc9e4bbbe65d4e
• https://github.com/sisimai/rb-sisimai/pull/244
• https://github.com/sisimai/rb-sisimai/releases/tag/v4.25.14p12
• https://vuldb.com/?ctiid.218452
• https://vuldb.com/?id.218452

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