The Acrobat JavaScript Blocklist Framework

Adobe Acrobat and Reader contain a buffer overflow (CWE-119) in their handling of arguments passed to JavaScript methods when rendering PDF files. An attacker triggers the flaw by convincing a user to open a crafted PDF whose embedded JavaScript calls methods with overly long arguments, and no user privileges beyond viewing the file are required. Successful exploitation allows a remote attacker to execute arbitrary code in the context of the user running Acrobat or Reader. Anyone running the affected Acrobat or Reader versions (specific version ranges are not provided in the source data) is affected, with Adobe Reader historically being one of the most widely deployed desktop applications. CISA added the vulnerability to the Known Exploited Vulnerabilities catalog on 2022-06-08, confirming exploitation in the wild, and EPSS assigns a 94% probability of exploitation within 30 days (100th percentile); no public proof-of-concept is known and ransomware use is unknown.

Do: Apply updates per vendor instructions by upgrading Acrobat and Reader to the patched releases Adobe made available for your version line, and audit the estate for legacy, unpatched Acrobat/Reader installs given the 2022 KEV listing. As an interim mitigation, disable or restrict JavaScript in the Acrobat/Reader preferences and treat PDFs from untrusted sources (email attachments, drive-by download sites, exploit-kit delivery channels) with caution.

Adobe Acrobat and Reader contain an input validation flaw (CWE-119, memory corruption) in a JavaScript method — historically the util.printf() JavaScript function — that fails to safely handle crafted arguments. An attacker triggers the flaw by getting a user to open a specially crafted PDF containing malicious JavaScript, which can corrupt memory and allow code execution on the victim's machine. Successful exploitation yields remote code execution with the privileges of the logged-in user, typically used to deliver malware; the related headlines indicate this flaw was folded into exploit kits and spam-driven malware campaigns of the era. Anyone running a vulnerable version of Adobe Acrobat or Reader (specific version ranges were not provided in the source data) with PDF JavaScript enabled is affected. Exploitation is confirmed in the wild: the flaw was added to CISA KEV on 2022-03-03 with known ransomware use, and EPSS assigns it a 98.5% probability of exploitation within 30 days.

Do: Apply updated versions of Acrobat and Reader per Adobe's instructions, as required by the CISA KEV listing. As an interim mitigation, disable or restrict JavaScript in Acrobat/Reader preferences (a JavaScript blocklist/allowlist approach, consistent with Adobe's JavaScript Blocklist Framework), and caution users against opening unsolicited PDFs, since exploitation has occurred via exploit kits, spam campaigns, and ransomware delivery. Check endpoints for unpatched Acrobat/Reader installs and confirm remediation against the CISA KEV deadline.

CVE-2009-0927 is a stack-based buffer overflow (improper input validation, CWE-20) in Adobe Reader and Adobe Acrobat that allows remote attackers to execute arbitrary code on the victim's system. The flaw is triggered when the PDF handling code in these products processes malicious input, typically via a specially crafted PDF document delivered through email, the web, or exploit kits. Successful exploitation gives an attacker the ability to run arbitrary code, generally with the privileges of the user running the PDF application. Any user or endpoint running an affected version of Adobe Reader or Acrobat is exposed, and given the near-universal deployment of these PDF tools the potential population is very large. The vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog (added 2022-03-25) with a required action to apply vendor updates, and EPSS assigns a 96.6% probability of exploitation within 30 days, though no public proof-of-concept is known.

Do: Apply updates per vendor instructions: upgrade all affected Adobe Reader and Acrobat installations to a patched release as required by the CISA KEV listing. As an interim mitigation, disable or restrict JavaScript in PDF files (the Acrobat JavaScript blocklist framework introduced around this period addresses this vector) and block PDFs from untrusted sources. Inventory endpoints for outdated Reader/Acrobat versions, prioritizing systems that open PDFs from email and the web.

CVE-2009-4324 is a use-after-free vulnerability in Adobe Acrobat and Adobe Reader in which a crafted PDF, typically using embedded JavaScript to invoke the media.newPlayer() multimedia API, frees an object that the program then reuses, corrupting memory. The flaw is triggered simply by opening the malicious PDF, so delivery as an email attachment or web download is enough, and successful exploitation gives an attacker arbitrary code execution with the rights of the logged-in user. Anyone running Acrobat or Reader versions current at the December 2009 disclosure was affected, which effectively meant the very large install base of the then-dominant PDF viewer, with observed attacks focused on Windows. The bug was exploited in the wild around the time of disclosure, with contemporaneous write-ups linking PDF-borne malware to Japan-earthquake-themed spam lures, and CISA added it to the Known Exploited Vulnerabilities catalog on 2022-06-08 (ransomware use: unknown). No standalone public proof-of-concept is catalogued, but EPSS ranks it in the 100th percentile with an approximately 82% probability of exploitation within 30 days, so defenders should treat it as actively exploited.

Do: Upgrade Acrobat and Reader to the fixed release in Adobe's January 2010 security update (APSB10-02), per the KEV required action; the versions vulnerable at disclosure are long past end-of-life, so any current deployment is unsupported and should be migrated. As interim mitigation, block or strip JavaScript and multimedia actions in PDFs (for example via Adobe's JavaScript blocklist framework or gateway-level PDF sanitization) and treat unsolicited PDF attachments as untrusted. Hunt on legacy Windows hosts for signs of PDF-borne code execution following receipt of themed spam or unexpected PDF attachments.