CVE-2025-0903
Published: 11 February 2025
Summary
CVE-2025-0903 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Pdf-Xchange Pdf-Xchange Editor. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked in the top 31.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Deeper analysis
CVE-2025-0903 is a heap-based buffer overflow vulnerability in PDF-XChange Editor that occurs during RTF file parsing. The flaw stems from insufficient validation of the length of user-supplied data before it is copied into a fixed-length heap buffer, enabling remote code execution. The affected component is the RTF parser within PDF-XChange Editor installations.
Remote attackers can exploit the issue by supplying a malicious RTF file or hosting one on a web page. Successful exploitation requires the victim to open the file or visit the page, after which arbitrary code runs in the context of the current process. The vulnerability carries a CVSS score of 8.8 and is tracked under CWEs 122 and 787; it was originally reported as ZDI-CAN-25421.
The single advisory reference points to the Zero Day Initiative disclosure for ZDI-25-070, which aligns with the published description but provides no additional mitigation details in the available record. The EPSS score started low, rose materially to a peak of 0.0226 on 2026-03-12, and has since receded to 0.0055, indicating that exploitation interest increased after disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-1918
Vulnerability details
PDF-XChange Editor RTF File Parsing Heap-based Buffer Overflow Remote 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…
more
visit a malicious page or open a malicious file. The specific flaw exists within the parsing of RTF files. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-25421.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Heap buffer overflow in client-side RTF parser directly enables T1203 (client application exploitation) and T1204.002 (malicious file execution) for RCE.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates the heap-based buffer overflow by requiring identification, reporting, and timely patching of the flaw in PDF-XChange Editor's RTF parsing.
Provides memory protections like DEP, ASLR, and stack canaries that prevent or complicate remote code execution from heap buffer overflows during RTF file parsing.
Mandates validation of user-supplied data lengths prior to copying into heap buffers, directly addressing the lack of bounds checking in RTF parsing.