CVE-2026-70345
Summary
by MITRE • 08/11/2026
Heap-based buffer overflow in Windows Installer allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 08/11/2026
A heap-based buffer overflow vulnerability exists within the windows installer component that enables authenticated attackers to achieve local privilege escalation. This vulnerability stems from improper input validation and memory management practices during the installation process where insufficient bounds checking allows malicious data to overwrite adjacent heap memory regions. The flaw manifests when the installer processes specially crafted package files or installation parameters that exceed allocated buffer sizes, leading to memory corruption that can be exploited to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability involves the manipulation of heap allocation structures and pointer references within the windows installer service. When legitimate users with standard privileges attempt to install malicious software packages, the installer fails to properly validate input lengths against predefined buffer boundaries. This memory corruption can overwrite critical function pointers or return addresses on the heap, enabling attackers to redirect execution flow and gain elevated system privileges through controlled code injection.
From an operational perspective this vulnerability presents significant risk to enterprise environments where standard users may have installation privileges or where legitimate software updates are frequently deployed. The local privilege escalation capability allows attackers to bypass typical user access controls and potentially establish persistent footholds within systems. Attackers can leverage this vulnerability by crafting malicious installation packages that trigger the buffer overflow condition during normal installation workflows, effectively transforming routine administrative tasks into privilege escalation opportunities.
The vulnerability aligns with CWE-121 heap-based buffer overflow classification and maps to several ATT&CK techniques including privilege escalation through exploitation of software vulnerabilities and execution through installation packages. Organizations should implement immediate mitigations including restricting user installation privileges, deploying application whitelisting controls, and ensuring timely patching of affected windows installer components. Additionally security monitoring should focus on unusual installation activities and process creation patterns that may indicate exploitation attempts. System administrators should also consider implementing least privilege principles for installation operations and regularly audit user permissions to minimize potential attack surfaces.