Security Resilience

CVE-2023-42040

Memory Safety in Pdf-Xchange Pdf-Tools 9.5.368.0

Memory Safety
Published
03 May 2024
Modified
19 May 2025
Patch / advisory
View advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0048 40th percentile
Risk Priority 61 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-2023-42040 is a high-severity Use After Free (CWE-416) vulnerability in Pdf-Xchange Pdf-Tools. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked at the 40th 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 SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

PDF-XChange Editor mailForm Use-After-Free Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of PDF-XChange Editor. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or…

more

open a malicious file. The specific flaw exists within the mailForm method. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-20663.

CWE(s)
CWE-416

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 →
T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
attack.mitre.org →
T1008 Fallback Channels Command And Control
Adversaries may use fallback or alternate communication channels if the primary channel is compromised or inaccessible in order to maintain reliable command and control and to avoid data transfer thresholds.
attack.mitre.org →
T1011 Exfiltration Over Other Network Medium Exfiltration
Adversaries may attempt to exfiltrate data over a different network medium than the command and control channel.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-6640Same product: Pdf-Xchange Pdf-Tools
CVE-2023-42082Same product: Pdf-Xchange Pdf-Tools
CVE-2023-39488Same product: Pdf-Xchange Pdf-Tools
CVE-2023-39491Same product: Pdf-Xchange Pdf-Tools
CVE-2023-42086Same product: Pdf-Xchange Pdf-Tools
CVE-2023-42041Same product: Pdf-Xchange Pdf-Tools
CVE-2025-6644Same product: Pdf-Xchange Pdf-Tools
CVE-2024-8816Same product: Pdf-Xchange Pdf-Tools
CVE-2025-6645Same product: Pdf-Xchange Pdf-Tools
CVE-2025-6661Same product: Pdf-Xchange Pdf-Tools

Affected Assets

pdf-xchange
pdf-tools
9.5.368.0
pdf-xchange
pdf-xchange editor
9.5.368.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.4.3

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover use-after-free bugs through dynamic analysis or fuzzing.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can require memory-safe constructs or languages that structurally avoid introducing use-after-free.

SC-39 Process Isolation partial match

Process isolation confines the blast radius of use-after-free memory corruption to a single execution domain.

SI-16 Memory Protection partial match

Memory protection controls limit exploitation impact by blocking unauthorized code execution from dangling pointers.

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.

ID.RA-01 partial match
blocks

Vulnerability identification processes can discover use-after-free issues via scanning or analysis but do not prevent their introduction.

PR.PS-02 partial match
blocks

Routine patching removes known use-after-free instances after they have been introduced in released software.

PR.PS-06 partial match
blocks

Secure SDLC practices directly incorporate memory-safety tooling and reviews that prevent most use-after-free defects.

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.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.5.30 ICT readiness for business continuity partial match
removes

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248592 OL 8 must clear memory when it is freed to prevent use-after-free attacks. blocks CWE-416
RHEL 8 (1 rule)
  • V-230279 RHEL 8 must clear memory when it is freed to prevent use-after-free attacks. blocks CWE-416
RHEL 9 (1 rule)
  • V-257794 RHEL 9 must clear memory when it is freed to prevent use-after-free attacks. blocks CWE-416

References