CVE-2021-29096 in ArcReader
Summary
by MITRE • 03/25/2021
A use-after-free vulnerability when parsing a specially crafted file in Esri ArcReader, ArcGIS Desktop, ArcGIS Engine 10.8.1 (and earlier) and ArcGIS Pro 2.7 (and earlier) allows an unauthenticated attacker to achieve arbitrary code execution in the context of the current user.
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Analysis
by VulDB Data Team • 04/05/2021
The vulnerability identified as CVE-2021-29096 represents a critical use-after-free flaw within Esri's geographic information system software suite, specifically affecting ArcReader, ArcGIS Desktop, ArcGIS Engine 10.8.1 and earlier versions, as well as ArcGIS Pro 2.7 and earlier releases. This vulnerability stems from improper memory management during the parsing of specially crafted files, creating a scenario where freed memory locations are subsequently accessed, leading to potential code execution. The flaw exists in the software's file processing mechanisms, particularly when handling malformed or maliciously constructed data files that exploit the underlying memory allocation patterns.
From a technical perspective, this use-after-free vulnerability operates through a classic memory safety issue where the application allocates memory for file parsing operations, frees that memory upon completion of processing, but subsequently attempts to access the same memory locations during subsequent operations. The attack vector involves an unauthenticated remote attacker who can craft malicious files designed to trigger this specific memory management flaw. When the vulnerable software processes these crafted files, the improper handling of freed memory creates opportunities for attackers to manipulate the program's execution flow, potentially leading to arbitrary code execution with the privileges of the current user. This vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software applications.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to execute malicious code on targeted systems without requiring authentication or prior access. The affected software ecosystem represents critical infrastructure for many organizations, particularly those in government, defense, and enterprise sectors that rely on Esri's mapping and GIS solutions. The vulnerability's exploitation potential means that attackers could gain unauthorized access to sensitive geographic data, modify system configurations, or establish persistent access points within networks. This threat is particularly concerning given that the vulnerable versions of these applications are widely deployed across organizations that may not have immediate patching capabilities or awareness of the specific vulnerability.
Security mitigations for CVE-2021-29096 primarily focus on immediate software updates and patches provided by Esri, which address the underlying memory management issues in the file parsing routines. Organizations should prioritize applying these patches across all affected versions of ArcReader, ArcGIS Desktop, ArcGIS Engine, and ArcGIS Pro to prevent exploitation. Additionally, network segmentation and access controls should be implemented to limit exposure of vulnerable systems to untrusted file sources. Security monitoring should include detection of suspicious file processing activities and unusual memory allocation patterns that might indicate exploitation attempts. The vulnerability's classification under ATT&CK technique T1059.007 for command and script interpreter indicates that exploitation could enable attackers to establish persistent command execution capabilities. Organizations should also implement file validation procedures and restrict user permissions to minimize potential impact if exploitation occurs, while maintaining awareness of potential social engineering vectors that might deliver malicious files to these applications.