What’s Vulnerable › Vulnerabilities

CVE-2023-5770: HTML injection in email body through email subject

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-01-09 · updated 2026-06-17
• Weakness: CWE-838

Description

Proofpoint Enterprise Protection contains a vulnerability in the email delivery agent that allows an unauthenticated attacker to inject improperly encoded HTML into the email body of a message through the email subject. The vulnerability is caused by inappropriate encoding when rewriting the email before delivery.This issue affects Proofpoint Enterprise Protection: from 8.20.2 before patch 4809, from 8.20.0 before patch 4805, from 8.18.6 before patch 4804 and all other prior versions.

Affected products

• Proofpoint Enterprise Protection: 8.18.6, 8.20.0, 8.20.2

References

• https://www.proofpoint.com/us/security/security-advisories/pfpt-sa-2023-0009
• https://www.proofpoint.com/us/security/security-advisories/pfpt-sa-2023-0009

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