CVE-2023-5771 | HTML injection in AdminUI through email subject

Proofpoint Enterprise Protection contains a stored XSS vulnerability in the AdminUI. An unauthenticated attacker can send a specially crafted email with HTML in the subject which triggers XSS when viewing quarantined messages.  This issue affects Proofpoint Enterprise Protection: from 8.20.0 before patch 4796, from 8.18.6 before patch 4795 and all other prior versions.

Published: 2023-11-06 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-5771 is rated Low Risk (37/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.15%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-5771

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.26% 0.15% -0.10%
2 2025-11-18 0.15% 0.26% +0.10%
3 2025-04-15 — 0.15% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-5771

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]

Weakness enumeration for CVE-2023-5771

Affected software / configurations for CVE-2023-5771

Vendor Product Version Raw CPE
proofpoint enterprise_protection < 8.18.6 cpe:2.3:a:proofpoint:enterprise_protection:*:*:*:*:*:*:*:*
proofpoint enterprise_protection 8.18.6 cpe:2.3:a:proofpoint:enterprise_protection:8.18.6:-:*:*:*:*:*:*
proofpoint enterprise_protection 8.20.0 cpe:2.3:a:proofpoint:enterprise_protection:8.20.0:-:*:*:*:*:*:*

References for CVE-2023-5771

cvelogic Threat Intelligence