CVE-2017-0356: Authentication bypass via repeated parameters

Severity: critical (CVSS 9.8 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2018-04-13 · updated 2026-06-17
Weakness: CWE-287

Description

A flaw, similar to to CVE-2016-9646, exists in ikiwiki before 3.20170111, in the passwordauth plugin's use of CGI::FormBuilder, allowing an attacker to bypass authentication via repeated parameters.

Affected products

Debian Linux: 7.0, 8.0
ikiwiki: before 3.20170111 — fixed in 3.20170111

How to fix

Upgrade to a fixed version: ikiwiki 3.20170111. Check the vendor advisory for mitigations.

References

http://www.securityfocus.com/bid/95420
https://ikiwiki.info/security/#cve-2017-0356
https://marc.info/?l=oss-security&m=148418234314276&w=2
https://www.debian.org/security/2017/dsa-3760
http://www.securityfocus.com/bid/95420
https://ikiwiki.info/security/#cve-2017-0356
https://marc.info/?l=oss-security&m=148418234314276&w=2
https://www.debian.org/security/2017/dsa-3760

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