CVE-2020-22840Public exploitNetwork attack vector

Phishing redirects via unchecked destination parameter

Published Feb 9, 2021 · Updated Aug 4, 2024

Open redirect in b2evolution CMS before 6.11.6 allows remote attackers to send users to attacker-controlled sites via crafted links. The htsrv/email_passthrough.php endpoint accepts the redirect_to query parameter as an external destination and redirects without restricting it to a trusted origin. No authentication is required, but a user must follow the crafted URL; the resulting domain transition supports phishing rather than direct server compromise.

CVSS severity6.1
Medium
EPSS probability13.82%
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 b2evolution CMS before 6.11.6 allows remote attackers to send users to attacker-controlled sites via crafted links. The htsrv/email_passthrough.php endpoint accepts the redirect_to query parameter as an external destination and redirects without restricting it to a trusted origin. No authentication is required, but a user must follow the crafted URL; the resulting domain transition supports phishing rather than direct server compromise.

The record

CVE
CVE-2020-22840
Published
Feb 9, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-601, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

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

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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')
T1204.001User Execution: Malicious Link

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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