Exploit kits attack vector – mid

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-2010-0840 is an unspecified vulnerability in the Java Runtime Environment (JRE) component of Oracle Java SE that allows remote attackers to affect confidentiality, integrity, and availability through vectors Oracle did not publicly detail. Because the advisory withheld technical specifics, the exact trigger is undocumented, but the flaw is remotely exploitable, and the era's threat reporting (2011 exploit-kit and Java malware headlines) is consistent with drive-by exploitation of Java clients. A successful attacker gains the ability to compromise the confidentiality, integrity, or availability of the affected system, and Java flaws of this period were commonly leveraged to install malware such as bots. Any organization or end user running the affected JRE releases — whether the browser Java plug-in on desktops or server-side Java — is exposed, making the affected population extremely broad. The flaw is listed in CISA's Known Exploited Vulnerabilities catalog (added 2022-05-25), EPSS assigns it a 96.3% probability of exploitation in the next 30 days, and no public proof-of-concept is known.

Do: Apply the Oracle Java SE updates specified by the vendor as required by CISA's KEV listing, and remove or disable obsolete or unsupported JRE versions, especially the browser Java plug-in where it is no longer needed. Prioritize internet-exposed and end-user systems, check for lingering legacy Java applets in use, and note that remediation is mandatory for federal agencies under the KEV program.