CVE-2024-9740 Overview
CVE-2024-9740 is an out-of-bounds write vulnerability [CWE-787] in Tungsten Automation Power PDF. The flaw exists in the parser that processes BMP image files and stems from missing validation of user-supplied data. An attacker who convinces a user to open a crafted BMP file or a document that embeds one can execute arbitrary code in the context of the current process. The issue was reported through the Zero Day Initiative as ZDI-CAN-24456 and published as advisory ZDI-24-1343.
Critical Impact
Successful exploitation yields arbitrary code execution on the target endpoint with the privileges of the Power PDF user, enabling foothold establishment and follow-on compromise.
Affected Products
- Tungsten Automation Power PDF
- Products embedding the Power PDF BMP parser component
- Workstations processing untrusted BMP or PDF content through Power PDF
Discovery Timeline
- 2024-11-22 - CVE-2024-9740 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-9740
Vulnerability Analysis
The vulnerability resides in the BMP image parsing routine used by Power PDF. When the parser processes a crafted bitmap, it writes data past the end of an allocated buffer. This out-of-bounds write corrupts adjacent heap or stack memory managed by the Power PDF process.
Attackers can shape the malformed BMP so the overflow overwrites function pointers, virtual method tables, or return addresses. This converts the memory corruption into control-flow hijacking and arbitrary code execution. Exploitation requires user interaction: the victim must open a malicious file or visit a page that delivers one.
The issue is classified under [CWE-787: Out-of-Bounds Write] and tracked by the Zero Day Initiative as ZDI-CAN-24456. Full technical details are available in the Zero Day Initiative Advisory ZDI-24-1343.
Root Cause
The BMP parser trusts size and offset fields inside the bitmap header without validating them against the destination buffer. When these fields exceed the allocated object, the copy operation writes past the buffer boundary and corrupts adjacent memory structures.
Attack Vector
Exploitation is local and file-based. An attacker delivers a crafted BMP directly or embeds it within a PDF or web page. When the victim opens the file in Power PDF, the parser triggers the out-of-bounds write and executes attacker-controlled code. No authentication is required, but user interaction is mandatory.
No public proof-of-concept exploit code is available. See the Zero Day Initiative Advisory ZDI-24-1343 for the vendor-coordinated technical details.
Detection Methods for CVE-2024-9740
Indicators of Compromise
- Unexpected child processes spawned by the Power PDF executable, such as cmd.exe, powershell.exe, or rundll32.exe.
- Power PDF process crashes with access violation exceptions immediately after opening a BMP or PDF document.
- BMP files with malformed header fields (invalid biSize, biWidth, or biHeight values) arriving via email or download.
Detection Strategies
- Alert on Power PDF processes performing network connections or writing to autorun and startup locations.
- Use EDR telemetry to flag heap corruption exceptions and unexpected memory allocation patterns in the Power PDF process.
- Inspect email and web gateway traffic for BMP payloads embedded in PDF attachments from untrusted senders.
Monitoring Recommendations
- Correlate document-open events with subsequent process creation, module loads, and outbound connections.
- Track file writes by Power PDF into user profile paths that indicate persistence, including %APPDATA% and Startup folders.
- Retain document parsing crash telemetry to identify targeted exploitation attempts against unpatched hosts.
How to Mitigate CVE-2024-9740
Immediate Actions Required
- Apply the vendor update for Tungsten Automation Power PDF referenced in ZDI advisory ZDI-24-1343 as soon as it is available.
- Block inbound BMP files and BMP-embedded PDFs from untrusted senders at the mail and web gateway.
- Instruct users to avoid opening PDF or BMP files from unknown sources until patching is complete.
Patch Information
Refer to the Zero Day Initiative Advisory ZDI-24-1343 for coordinated disclosure details and consult Tungsten Automation's Power PDF release notes for the fixed version. No vendor advisory URL is listed in NVD at time of publication.
Workarounds
- Disassociate BMP and PDF file types from Power PDF on endpoints that do not require the application.
- Restrict Power PDF execution using application allowlisting for high-risk user populations.
- Enforce standard user privileges so a compromised Power PDF process cannot escalate to administrative context.
# Configuration example: block BMP attachments at an SMTP gateway (Postfix header_checks)
/name=[^>]*\.bmp/ REJECT BMP attachments blocked pending CVE-2024-9740 remediation
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
