CVE-2011-3112 in Chrome
Summary
by MITRE
Use-after-free vulnerability in the PDF functionality in Google Chrome before 19.0.1084.52 allows remote attackers to cause a denial of service or possibly have unspecified other impact via an invalid encrypted document.
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Analysis
by VulDB Data Team • 03/25/2021
The vulnerability identified as CVE-2011-3112 represents a critical use-after-free flaw within Google Chrome's PDF rendering functionality, specifically affecting versions prior to 19.0.1084.52. This type of vulnerability occurs when a program continues to reference memory that has already been freed, creating potential exploitation vectors for malicious actors. The issue manifests within the PDF handling component of the browser, which processes and renders PDF documents through a dedicated plugin or built-in engine. The vulnerability is particularly concerning because it can be triggered through the manipulation of PDF documents, specifically encrypted ones that contain invalid structures or malformed data.
The technical exploitation of this use-after-free vulnerability enables remote attackers to manipulate memory pointers within Chrome's PDF processing pipeline. When Chrome encounters an invalid encrypted PDF document, the memory management system fails to properly handle the deallocation of memory resources, creating a scenario where subsequent operations attempt to access previously freed memory locations. This memory corruption can result in unpredictable behavior including application crashes, denial of service conditions, or potentially more severe consequences depending on the specific memory layout and exploitation techniques employed. The vulnerability's impact extends beyond simple denial of service as it may enable arbitrary code execution under certain conditions.
From an operational perspective, this vulnerability presents significant risks to users who frequently interact with PDF documents from untrusted sources. The remote exploitation capability means that attackers can craft malicious PDF files that, when opened in vulnerable Chrome versions, will trigger the memory corruption. This makes the vulnerability particularly dangerous in phishing campaigns, malicious email attachments, or compromised websites that serve malicious PDF content. The potential for unspecified other impacts suggests that exploitation might lead to more serious consequences beyond simple service disruption, potentially allowing for privilege escalation or complete system compromise depending on the execution environment and memory layout.
The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software systems, and demonstrates how memory safety issues can be exploited in browser environments where complex document processing occurs. From an adversarial perspective, this vulnerability maps to several ATT&CK techniques including initial access through malicious documents, and privilege escalation if exploitation leads to code execution. The remediation strategy involves immediate updating of Chrome to version 19.0.1084.52 or later, which includes memory management fixes and improved validation of PDF document structures. Organizations should also implement network-based protections such as PDF content filtering, browser hardening measures, and user education about avoiding untrusted PDF documents. Additionally, regular security assessments of browser configurations and monitoring for suspicious PDF-related activities can help detect potential exploitation attempts.