CVE-2020-36599Network attack vector

Failure redirect manipulation via unescaped message key

Published Aug 18, 2022 · Updated Aug 4, 2024

Output-encoding flaw in OmniAuth before 1.9.2 and 2.0.0.pre.rc1 allows remote attackers to alter failure redirect URLs. FailureEndpoint inserts the unescaped message_key into the Location header query string, so reserved characters can change the redirect URL structure. Exploitation requires a deployed strategy to place an attacker-influenced error type in omniauth.error.type; published sources do not specify consequences beyond redirect manipulation.

CVSS severity9.8
Critical
EPSS probability1.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Output-encoding flaw in OmniAuth before 1.9.2 and 2.0.0.pre.rc1 allows remote attackers to alter failure redirect URLs. FailureEndpoint inserts the unescaped message_key into the Location header query string, so reserved characters can change the redirect URL structure. Exploitation requires a deployed strategy to place an attacker-influenced error type in omniauth.error.type; published sources do not specify consequences beyond redirect manipulation.

The record

CVE
CVE-2020-36599
Published
Aug 18, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-116
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 18, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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

9.8GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-116Improper Encoding or Escaping of Output

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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