CVE-2023-5770 - CVE House
Back to Database
Status published Medium CVE-2023-5770

HTML injection in email body through email subject

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

THREAT MONITOR

Am I Vulnerable?

Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2023-5770

Credits & Attribution

No credits recorded in the NVD database.

References

More from Proofpoint

View All →
CVE-2025-8558
Insider Threat Management (ITM) Server versions prior to 7.17.2 contain an authentication...
Low 2.3
CVE-2025-0431
Enterprise Protection Backslash URL Rewrite Bypass
Medium 5.8
CVE-2024-3676
The Proofpoint Encryption endpoint of Proofpoint Enterprise Protection contains an...
High 7.5
CVE-2024-10635
Enterprise Protection S/MIME Opaque Signature Attachment Scanning Bypass
Medium 6.1
CVE-2024-0862
The Proofpoint Encryption endpoint of Proofpoint Enterprise Protection contains a...
Medium 5

Affected Vendor

Affected Software

Proofpoint Enterprise Protection
Vulnerable Versions:
8.20.2, 8.20.0, 8.18.6, 8.0

Timeline

Official Publish: January 9th, 2024
Last Modified: June 3rd, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Weaknesses (CWE)

CWE-838

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.