CVE-2025-0431Network attack vector

URL protection bypass via unfiltered backslashes

Published Mar 19, 2025 · Updated Mar 19, 2025

URL-rewriting bypass in Proofpoint Enterprise Protection allows remote attackers to send email that evades URL protections. Its URL rewriter improperly filters backslashes in attacker-supplied URLs, causing crafted links to escape the intended protection. No authentication or user interaction is required; successful messages reach recipients without the intended URL-integrity control.

CVSS severity5.8
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

URL-rewriting bypass in Proofpoint Enterprise Protection allows remote attackers to send email that evades URL protections. Its URL rewriter improperly filters backslashes in attacker-supplied URLs, causing crafted links to escape the intended protection. No authentication or user interaction is required; successful messages reach recipients without the intended URL-integrity control.

The record

CVE
CVE-2025-0431
Published
Mar 19, 2025
Updated
Mar 19, 2025
Vendor
Proofpoint
Product
Proofpoint Enterprise Protection
Classifications
CWE-790, T1566.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Mar 19, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=8.18.6 <patch 5113 changes=[{"at":"patch 5113","status":"unaffected"}]
  2. Affected versionversion=8.20.6 <patch 5114 changes=[{"at":"patch 5114","status":"unaffected"}]
  3. Affected versionversion=8.21.0 <patch 5115 changes=[{"at":"patch 5115","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Proofpoint · Proofpoint Enterprise Protectionversion=8.18.6 <patch 5113 changes=[{"at":"patch 5113","status":"unaffected"}]; version=8.20.6 <patch 5114 changes=[{"at":"patch 5114","status":"unaffected"}]; version=8.21.0 <patch 5115 changes=[{"at":"patch 5115","status":"unaffected"}]

Published CVSS scores

5.8ProofpointCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/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 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 exploitUnconfirmed

Weakness, pattern, technique

CWE-790Improper Filtering of Special Elements
T1566.002Spearphishing Link

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo