CVE-2019-20479Public exploitNetwork attack vector

Open redirect via slash-backslash logout URL

Published Feb 20, 2020 · Updated Aug 5, 2024

Open redirect in OpenIDC mod_auth_openidc before 2.4.1 allows remote attackers to redirect users to attacker-controlled sites. The oidc_validate_post_logout_url function accepts a post-logout URL beginning with slash-backslash when parsing returns no hostname, then places it in the Location header. Exploitation requires a user to follow a crafted logout link; the browser treats the malformed path as an external destination, supporting phishing.

CVSS severity6.1
Medium
EPSS probability1.89%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Open redirect in OpenIDC mod_auth_openidc before 2.4.1 allows remote attackers to redirect users to attacker-controlled sites. The oidc_validate_post_logout_url function accepts a post-logout URL beginning with slash-backslash when parsing returns no hostname, then places it in the Location header. Exploitation requires a user to follow a crafted logout link; the browser treats the malformed path as an external destination, supporting phishing.

The record

CVE
CVE-2019-20479
Published
Feb 20, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-601
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 20, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-601URL Redirection to Untrusted Site ('Open Redirect')

Public exploit references

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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