Security Resilience

CVE-2023-5770

Proofpoint Enterprise Protection 8.18.6 … 8.20.2

Published
09 January 2024
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.0034 26th percentile
Risk Priority 44 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-5770 is a medium-severity Inappropriate Encoding for Output Context (CWE-838) vulnerability in Proofpoint Enterprise Protection. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked at the 26th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-15 (Information Output Filtering) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-838

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
attack.mitre.org →
T1003.003 NTDS Credential Access
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights.
attack.mitre.org →
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
attack.mitre.org →
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
attack.mitre.org →
T1010 Application Window Discovery Discovery
Adversaries may attempt to get a listing of open application windows.
attack.mitre.org →
T1016 System Network Configuration Discovery Discovery
Adversaries may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-0090Same product: Proofpoint Enterprise Protection
CVE-2023-0089Same product: Proofpoint Enterprise Protection
CVE-2023-5771Same product: Proofpoint Enterprise Protection
CVE-2024-10635Same product: Proofpoint Enterprise Protection
CVE-2023-3735Shared CWE-838
CVE-2023-6512Shared CWE-838
CVE-2024-34006Shared CWE-838
CVE-2025-4052Shared CWE-838
CVE-2024-11702Shared CWE-838
CVE-2023-2818Same vendor: Proofpoint

Affected Assets

proofpoint
enterprise protection
8.18.6, 8.20.0, 8.20.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.1
  • V1.2.2
  • V1.2.3
  • V1.2.5

Mitigating Controls (NIST 800-53 r5) AI

SI-15 Information Output Filtering good match

Validates output data representations to ensure consistency with expected formats, directly stopping encoding mismatches for downstream contexts.

SA-8 Security and Privacy Engineering Principles partial match

Requires application of secure engineering principles during development that include correct output encoding for context.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
blocks

Secure SDLC practices directly require correct output encoding to match downstream context, but eliminating only this flaw covers a narrow slice of the broader control.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.25 Secure development life cycle partial match
blocks

Secure development life cycle requires encoding-aware output handling, but does not mandate context-specific encoding checks.

A.8.26 Application security requirements partial match
blocks

Application security requirements can specify correct output encoding, yet the control is broader than this single weakness.

A.8.28 Secure coding partial match
prevents

Secure coding directly addresses proper output encoding for context, covering most of the weakness and the control's intent.

A.8.29 Security testing in development and acceptance partial match
finds

Security testing can detect encoding mismatches, but testing alone does not prevent the weakness at source.

A.8.8 Management of technical vulnerabilities partial match
removes
A.8.9 Configuration management partial match
removes

References