CVE-2024-20765 Overview
CVE-2024-20765 is a use-after-free vulnerability affecting Adobe Acrobat and Acrobat Reader on Windows and macOS. Adobe Acrobat Reader versions 20.005.30539, 23.008.20470, and earlier contain the flaw. Attackers can achieve arbitrary code execution in the context of the current user by convincing a victim to open a crafted PDF file. The vulnerability is tracked under CWE-416: Use After Free and requires local user interaction to exploit. Adobe published fixes in the APSB24-07 security advisory in February 2024.
Critical Impact
Successful exploitation grants arbitrary code execution with the privileges of the user opening the malicious PDF, enabling malware deployment, credential theft, or lateral movement.
Affected Products
- Adobe Acrobat and Acrobat DC (Classic and Continuous tracks) versions 20.005.30539, 23.008.20470, and earlier
- Adobe Acrobat Reader and Acrobat Reader DC (Classic and Continuous tracks) versions 20.005.30539, 23.008.20470, and earlier
- Microsoft Windows and Apple macOS installations of the above products
Discovery Timeline
- 2024-02-29 - CVE-2024-20765 published to NVD following Adobe's APSB24-07 advisory
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-20765
Vulnerability Analysis
The flaw is a use-after-free condition inside Adobe Acrobat and Reader's PDF processing logic. Use-after-free occurs when code continues to reference memory after that memory has been freed. An attacker who controls the contents of a PDF can influence which object occupies the freed region, then trigger dereference of the stale pointer. This primitive typically enables arbitrary read, write, or control-flow hijacking depending on the freed object's layout.
Exploitation requires the victim to open a malicious PDF in a vulnerable Acrobat or Reader build. Because the attack executes locally after user interaction, phishing campaigns and drive-by download workflows remain the primary delivery paths. The current EPSS score of 0.562% indicates a modest but non-trivial probability of exploitation activity. No public proof-of-concept exploit or CISA Known Exploited Vulnerabilities listing exists as of this writing.
Root Cause
The root cause is improper object lifetime management within Acrobat's parsing or rendering pipeline. A specific object is freed while another code path retains a reference to it. When that reference is later dereferenced, the memory has been reallocated with attacker-influenced data. The condition falls under CWE-416.
Attack Vector
The attack vector is local and requires user interaction. An attacker delivers a crafted PDF through email, chat, a compromised website, or a shared file store. When the victim opens the file in vulnerable Acrobat or Reader, the parser triggers the use-after-free. Successful exploitation typically leverages heap grooming to place a controlled object into the freed slot, followed by a chain that bypasses Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) to run shellcode as the current user.
Adobe has not published exploitation code, and no verified public proof-of-concept exists. Refer to the Adobe Acrobat security advisory APSB24-07 for vendor-supplied technical details.
Detection Methods for CVE-2024-20765
Indicators of Compromise
- Unexpected child processes spawned from AcroRd32.exe or Acrobat.exe, such as cmd.exe, powershell.exe, or rundll32.exe
- Acrobat or Reader process crashes with access-violation exceptions immediately after opening a PDF
- PDF files received from untrusted sources containing embedded JavaScript, unusual object streams, or malformed cross-reference tables
- Outbound network connections initiated by Acrobat processes to previously unseen hosts shortly after document open
Detection Strategies
- Monitor process ancestry for Acrobat and Reader spawning shells, scripting engines, or LOLBins
- Alert on Acrobat crash dumps or Windows Error Reporting events tied to PDF handlers
- Inspect inbound PDFs at the mail gateway for anomalous object structures and embedded active content
- Correlate document-open telemetry with subsequent file writes to user-writable persistence locations
Monitoring Recommendations
- Ingest endpoint process, file, and network telemetry into a centralized analytics platform and retain sufficient history for retrospective hunts
- Track Acrobat and Reader version inventory across the fleet to identify unpatched hosts running 20.005.30539, 23.008.20470, or earlier builds
- Enable Protected View and Protected Mode logging and forward those events to the SIEM
How to Mitigate CVE-2024-20765
Immediate Actions Required
- Update Adobe Acrobat and Acrobat Reader to the fixed versions listed in APSB24-07 across Windows and macOS endpoints
- Confirm automatic updates are enabled and force a check-in on managed endpoints to accelerate deployment
- Block or quarantine PDFs from untrusted external senders at the mail and web gateways until patching completes
- Restrict end-user privileges so a compromised Acrobat process cannot escalate beyond the user context
Patch Information
Adobe released updates addressing CVE-2024-20765 in security bulletin APSB24-07 on February 29, 2024. Administrators should deploy the fixed builds published in that advisory for both the Classic and Continuous tracks of Acrobat and Acrobat Reader. Verify installed versions post-deployment using software inventory tooling.
Workarounds
- Enable Protected View and Protected Mode in Acrobat and Reader to sandbox rendering of PDFs from untrusted locations
- Disable JavaScript execution in Acrobat preferences to reduce the attack surface for PDF-based exploits
- Configure Attack Surface Reduction rules on Windows to block Office and PDF applications from spawning child processes
- Use application allow-listing to prevent Acrobat processes from launching unauthorized executables
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
