CVE-2021-37597Public exploitNetwork attack vector

Administrative MFA bypass via cookie manipulation

Published Aug 19, 2021 · Updated Aug 4, 2024

Authentication bypass in WP Cerber before 8.9.3 allows remote authenticated users to access protected WordPress pages without the MFA PIN via a crafted login cookie. The plugin accepts deletion or one-character changes to the wordpress_logged_in_[hash] cookie during authentication, allowing the session to pass MFA checks. Attackers still need a valid username and password; successful exploitation exposes functionality and information available to that account.

CVSS severity9.8
Critical
EPSS probability2.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in WP Cerber before 8.9.3 allows remote authenticated users to access protected WordPress pages without the MFA PIN via a crafted login cookie. The plugin accepts deletion or one-character changes to the wordpress_logged_in_[hash] cookie during authentication, allowing the session to pass MFA checks. Attackers still need a valid username and password; successful exploitation exposes functionality and information available to that account.

The record

CVE
CVE-2021-37597
Published
Aug 19, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-287, T1556.006
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 2021CVE 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NVDCVSS: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.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
T1556.006Multi-Factor Authentication Interception

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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