Rule Category

FILE-PDF -- Snort has detected suspicious traffic related to a PDF file. PDFs are easily exploitable. They include many ways to encapsulate data and are often targeted by attackers, who use the PDF's household name status for social engineering. Therefore, Snort includes Many PDF-targeted rules.

Alert Message

FILE-PDF FreeType PostScript Type1 font parsing memory corruption attempt

Rule Explanation

Integer signedness error in psaux/t1decode.c in FreeType before 2.4.6, as used in CoreGraphics in Apple iOS before 4.2.9 and 4.3.x before 4.3.4 and other products, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted Type 1 font in a PDF document, as exploited in the wild in July 2011.

What To Look For

This rule alerts when an known exploit for certain FreeType library versions is detected.

Known Usage

No public information

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group

MITRE ATT&CK Framework

Tactic: Initial Access

Technique: Drive-by Compromise

For reference, see the MITRE ATT&CK vulnerability types here: https://attack.mitre.org

CVE

Rule Vulnerability

Memory Corruption

Memory Corruption is any vulnerability that allows the modification of the content of memory locations in a way not intended by the developer. Memory corruption results are inconsistent; they could lead to fatal errors and system crashes or data leakage; some have no effect at all.

CVE Additional Information

CVE-2011-0226
Integer signedness error in psaux/t1decode.c in FreeType before 2.4.6, as used in CoreGraphics in Apple iOS before 4.2.9 and 4.3.x before 4.3.4 and other products, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted Type 1 font in a PDF document, as exploited in the wild in July 2011.
Details
SeverityHIGH Base Score9.3
Impact Score10.0 Exploit Score8.6
Confidentiality ImpactCOMPLETE Integrity ImpactCOMPLETE
Availability ImpactCOMPLETE Access Vector
AuthenticationNONE Ease of Access