Cyber Resilience

CVE-2023-45727

XXE in Northgrid Proself ≤ 1.09

CISA KEVActive ExploitationEUVD ExploitedXXE
Published
18 October 2023
Modified
24 October 2025
KEV Added
03 December 2024
Patch / advisory
View advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.035 88th percentile
Risk Priority 84 floored blend · peak EPSS

Summary

CVE-2023-45727 is a high-severity Improper Restriction of XML External Entity Reference (CWE-611) vulnerability in Northgrid Proself. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 12% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-45727 is an XML External Entity (XXE) vulnerability, tracked under CWE-611, that affects Proself Enterprise/Standard Edition versions 5.62 and earlier, Proself Gateway Edition versions 1.65 and earlier, and Proself Mail Sanitize Edition versions 1.08 and earlier. The flaw resides in the products' handling of XML input and permits a remote attacker to supply malformed XML data that triggers external entity resolution.

An unauthenticated attacker can send a specially crafted request over the network to read arbitrary files on the server, including those that contain account information. The attack requires no user interaction or credentials and carries a CVSS 3.1 score of 7.5, reflecting high confidentiality impact with no integrity or availability effects.

Vendor advisories from Proself and JVN recommend upgrading to fixed versions that disable or properly configure XML entity processing. The vulnerability also appears in the CISA Known Exploited Vulnerabilities catalog, confirming observed in-the-wild exploitation.

EPSS scores for the CVE rose from a low baseline to a peak of 0.4148 on 2024-12-12 before receding to the current value of 0.2105, indicating that exploitation interest increased after public disclosure.

OWASP Top 10 for Web (2025)

A02:2025 Security Misconfiguration

EU & UK References

Vulnerability Data

Proself Enterprise/Standard Edition Ver5.62 and earlier, Proself Gateway Edition Ver1.65 and earlier, and Proself Mail Sanitize Edition Ver1.08 and earlier allow a remote unauthenticated attacker to conduct XML External Entity (XXE) attacks. By processing a specially crafted request containing malformed…

more

XML data, arbitrary files on the server containing account information may be read by the attacker.

CWE(s)
CWE-611
KEV Date Added
03 December 2024

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
T1213 Data from Information Repositories Collection
Adversaries may leverage information repositories to mine valuable information.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-39416Same product: Northgrid Proself
CVE-2023-39415Same product: Northgrid Proself
CVE-2025-58360Shared CWE-611both on KEV
CVE-2019-9670Shared CWE-611both on KEV
CVE-2025-2776Shared CWE-611both on KEV
CVE-2016-9563Shared CWE-611both on KEV
CVE-2024-34102Shared CWE-611both on KEV
CVE-2019-13608Shared CWE-611both on KEV
CVE-2025-2775Shared CWE-611both on KEV
CVE-2023-29498Shared CWE-611

Affected Assets

northgrid
proself
≤ 1.09 · ≤ 1.66 · ≤ 5.63

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)
  • V1.5.1
  • V15.3.2

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing
addresses: CWE-611

Penetration testing includes XML external entity payloads, detecting XXE vulnerabilities and enabling their mitigation.

SI-4 System Monitoring
addresses: CWE-611

Identifies XML external entity processing via monitoring of unusual file/network access or resource usage.

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-01 mostly match
prevents

Hardened XML parser configurations directly disable external entity resolution.

PR.PS-06 mostly match
prevents

Secure SDLC practices include input validation and safe XML parser configuration that prevent XXE.

ID.RA-01 partial match
prevents

Vulnerability scanning can discover XXE flaws but does not prevent their introduction in code.

PR.PS-02 partial match
prevents

Patching eliminates XXE-vulnerable parser versions but is only one aspect of software maintenance.

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.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development catches XXE via static analysis and dynamic XML fuzzing.

A.8.8 Management of technical vulnerabilities mostly match
finds

Vulnerability management identifies and patches XML libraries with unsafe default entity settings.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and entity handling that directly prevents XXE.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for disabling external entity processing in XML parsers.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles include safe parser configuration that mitigates external entity risks.

A.8.28 Secure coding partial match
prevents

Secure coding standards require disabling DTDs and external entities in XML processing.

References