CVE-2021-36720Network attack vector

Cookie theft via reflected blocking.php URL

Published Dec 8, 2021 · Updated Aug 4, 2024

Reflected XSS in Cybonet PineApp Mail Secure before 5.2.1 allows remote attackers to steal cookies through a crafted blocking.php URL. The blocking.php handler places the url query parameter into its response without sufficient input validation, allowing supplied script markup to execute in a browser. Exploitation requires a user to open the crafted URL; script execution occurs in the appliance web interface's origin and can expose session cookies.

CVSS severity6.1
Medium
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Cybonet PineApp Mail Secure before 5.2.1 allows remote attackers to steal cookies through a crafted blocking.php URL. The blocking.php handler places the url query parameter into its response without sufficient input validation, allowing supplied script markup to execute in a browser. Exploitation requires a user to open the crafted URL; script execution occurs in the appliance web interface's origin and can expose session cookies.

The record

CVE
CVE-2021-36720
Published
Dec 8, 2021
Updated
Aug 4, 2024
Vendor
Cybonet
Product
PineApp Mail Secure
Classifications
CWE-79, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 8, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=PineApp - Mail Secure Latest

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Cybonet · PineApp Mail Secureversion=PineApp - Mail Secure Latest

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/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 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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1539Steal Web Session Cookie

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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