CVE-2026-108013 in BigFix Platform
Summary
by MITRE • 10/24/2026
BigFix Platform uses Mozilla CA certificate bundle (PEM). Versions of the bundle dated before 2026/10/20 still trust certificates whose private keys have been compromised. When BigFix Platform validates servers using such a bundle, an on-path attacker can impersonate remote servers and tamper with files downloaded by the application. The issue is resolved by using bundle version 2026/10/20 or later. The fixed bundle is available starting from BES Support v1520.
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Analysis
by VulDB Data Team • 10/24/2026
The BigFix Platform relies on a Mozilla CA certificate bundle in PEM format to validate the identity of remote servers during communication and file transfer operations. This trust model assumes that any certificate issued by a Certificate Authority present in the trusted store is valid and secure, thereby establishing an encrypted channel for data exchange. However, versions of this bundle dated prior to October 20, 2026, contain root certificates whose associated private keys have been compromised or are otherwise considered insecure due to advances in cryptanalysis or key management failures within those specific Certificate Authorities. This inclusion creates a significant trust anchor weakness where the platform implicitly trusts entities that should no longer be considered secure sources of identity verification.
This vulnerability allows for on-path attacks, commonly known as man-in-the-middle scenarios, against BigFix clients and servers. An attacker positioned between the client and the remote server can intercept communications by presenting a certificate signed by one of these compromised Certificate Authorities. Since the outdated bundle still trusts this authority, the BigFix application will accept the malicious certificate as valid without raising an alert or terminating the connection. Consequently, the attacker gains the ability to impersonate legitimate remote servers, effectively bypassing authentication mechanisms that rely on public key infrastructure validation.
The operational impact of this flaw is severe, particularly regarding data integrity and confidentiality during software distribution and patch management workflows. BigFix frequently downloads large files such as operating system images, application installers, and security patches from remote repositories. With the ability to impersonate these servers, an attacker can tamper with the downloaded content before it reaches the endpoint. This could involve injecting malicious code into legitimate updates, altering configuration scripts, or replacing critical binaries with compromised versions. Such actions facilitate widespread malware deployment, unauthorized system access, and potential compromise of entire enterprise networks that rely on BigFix for automated management tasks.
The resolution involves updating to a version of the Mozilla CA bundle dated October 20, 2026, or later, which removes trust in certificates associated with compromised private keys. This update is available starting from BES Support v1520 and ensures that only currently trusted and cryptographically secure Certificate Authorities are recognized by the platform. Administrators must verify their current BigFix server versions and apply this support pack to mitigate the risk of certificate-based impersonation attacks. Regularly updating CA bundles is a critical maintenance task in cybersecurity, as it aligns with industry best practices for maintaining trust anchors against evolving threats.
From a standards perspective, this vulnerability maps directly to CWE-295 Improper Certificate Validation and CWE-1038 The product uses an insecure cryptographic hash or public-key algorithm or key size when validating certificates from untrusted sources. In the context of the MITRE ATT&CK framework, this flaw enables techniques associated with T1499 Endpoint Denial of Service if availability is targeted, but more critically facilitates T1502 Use of Trusted Software for Lateral Movement and T1608 Install of Additional Components when malicious payloads are delivered via compromised updates. It also aligns with T1078 Valid Accounts if the attacker uses stolen credentials in conjunction with the impersonated connection to gain deeper access. Organizations should prioritize patching BigFix platforms immediately upon availability of v1520 or later and monitor for any anomalous certificate validation events that might indicate exploitation attempts against unpatched systems.