CVE-2017-0356 | Authentication bypass via repeated parameters

Exp

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.

Published: 2018-04-13 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-0356 is rated High Exploit Risk (84.7/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 3.46%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2017-0356

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2017-0356

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-18 3.60% 3.46% -0.14%
2 2026-06-15 3.27% 3.60% +0.33%
3 2026-06-04 — 3.27% —

Full EPSS history (23 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-0356

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2017-0356

OS Trackers for CVE-2017-0356

vendor priority summary link
debian not yet assigned CVE-2017-0356 not yet assigned priority: Debian including 1 source packages (ikiwiki), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2017-0356
ubuntu medium CVE-2017-0356 medium priority: Ubuntu including 1 source packages (ikiwiki), 23 status rows across 23 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, precise, questing, trusty, upstream, xenial, yakkety, zesty): not-affected 16, ignored 4, DNE 1, needed 1, released 1. https://ubuntu.com/security/CVE-2017-0356

Affected software / configurations for CVE-2017-0356

Vendor Product Version Raw CPE
ikiwiki ikiwiki < 3.20170111 cpe:2.3:a:ikiwiki:ikiwiki:*:*:*:*:*:*:*:*
debian debian_linux 7.0 cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*

References for CVE-2017-0356

cvelogic Threat Intelligence