CVE-2019-5530 in InstallBuilder
Summary
by MITRE
Windows binaries generated with InstallBuilder versions earlier than 19.7.0 are vulnerable to tampering even if they contain a valid Authenticode signature.
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Analysis
by VulDB Data Team • 12/07/2023
The vulnerability identified as CVE-2019-5530 represents a significant security flaw in the InstallBuilder software development toolkit that affects Windows installer binaries created with versions prior to 19.7.0. This issue fundamentally undermines the integrity verification mechanisms that users rely on when executing installation packages, creating a dangerous scenario where legitimate software can be modified without detection despite maintaining a valid Authenticode signature. The vulnerability stems from insufficient validation procedures within the InstallBuilder toolchain that fail to properly secure the installation packages against post-creation modifications.
The technical root cause of this vulnerability lies in the improper implementation of code signing verification processes within InstallBuilder versions before 19.7.0. When developers create Windows installers using these affected versions, the resulting binaries contain a valid Authenticode signature that appears legitimate to the operating system's security mechanisms. However, the underlying package structure does not adequately protect against modification attacks that can occur after the initial signing process. This flaw allows attackers to inject malicious code or alter existing functionality within the installer without breaking the signature validation, effectively bypassing the security controls that users expect from signed executables.
The operational impact of CVE-2019-5530 extends beyond simple code tampering, as it creates a false sense of security for end users and system administrators who rely on Authenticode signatures as a primary indicator of software integrity. Attackers can exploit this vulnerability by modifying legitimate installers to include backdoors, malware payloads, or other malicious components that will execute during the installation process. The vulnerability affects the core security model of Windows software distribution, where users trust that a valid signature indicates the software has not been compromised since signing. This compromise undermines the trust model that Authenticode signatures are designed to establish and can lead to widespread security breaches when exploited at scale.
Organizations and developers should immediately upgrade to InstallBuilder version 19.7.0 or later to remediate this vulnerability, as earlier versions contain the flawed signature validation logic that permits post-creation modifications without detection. System administrators should implement additional verification measures beyond signature validation, including hash checks and behavioral monitoring of installation processes. The vulnerability aligns with CWE-310, which addresses cryptographic issues related to signature validation and authentication failures. From an attack perspective, this vulnerability maps to multiple ATT&CK techniques including execution through legitimate system processes and privilege escalation via installation package manipulation. Security teams should also consider implementing network-based monitoring to detect anomalous installation behaviors that might indicate exploitation of this vulnerability, as traditional signature-based detection may not identify the modified installer components.