CVE-2020-8024 in openSUSE Leap
Summary
by MITRE
A Incorrect Default Permissions vulnerability in the packaging of hylafax+ of openSUSE Leap 15.2, openSUSE Leap 15.1, openSUSE Factory allows local attackers to escalate from user uucp to users calling hylafax binaries. This issue affects: openSUSE Leap 15.2 hylafax+ versions prior to 7.0.2-lp152.2.1. openSUSE Leap 15.1 hylafax+ version 5.6.1-lp151.3.7 and prior versions. openSUSE Factory hylafax+ versions prior to 7.0.2-2.1.
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Analysis
by VulDB Data Team • 10/27/2020
The CVE-2020-8024 vulnerability represents a critical incorrect default permissions flaw within the hylafax+ packaging distribution across multiple openSUSE versions. This vulnerability specifically targets the uucp user account which serves as a standard Unix user for handling dial-up communications and fax operations. The flaw allows local attackers to escalate their privileges from the uucp user level to higher-privileged user accounts that execute hylafax binaries, creating a significant security escalation path within the system. The vulnerability stems from improper file and directory permission settings during the packaging process, which should have enforced stricter access controls for fax-related system components.
The technical implementation of this vulnerability involves the misconfiguration of default permissions for critical system files and executables within the hylafax+ package structure. When hylafax+ binaries are executed, they typically operate with elevated privileges to manage fax communications, printer queues, and modem connections. However, due to the incorrect default permissions, the uucp user can manipulate these processes or access sensitive system resources that should otherwise be restricted. This misconfiguration creates a path where a local attacker with uucp privileges can leverage the system's trust relationships to gain access to higher-privileged accounts that are responsible for calling hylafax binaries, effectively breaking the principle of least privilege.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to gain unauthorized access to fax system configurations, modify fax routing rules, or even intercept and manipulate fax communications. The attack vector is particularly concerning because it requires only local system access, making it difficult to detect through network monitoring alone. This vulnerability affects the core fax infrastructure components that many organizations rely upon for critical business communications, potentially allowing attackers to disrupt fax services or access sensitive information transmitted through the fax system. The scope of impact covers multiple openSUSE distributions including Leap 15.2, Leap 15.1, and Factory, indicating a widespread packaging issue that required coordinated patching efforts across the openSUSE ecosystem.
Organizations should implement immediate mitigations including updating to the patched versions of hylafax+ as specified in the affected releases, typically versions 7.0.2-lp152.2.1 for Leap 15.2, 5.6.1-lp151.3.7 for Leap 15.1, and 7.0.2-2.1 for Factory. System administrators should also conduct thorough permission audits of fax-related directories and files to ensure no residual misconfigurations persist after patching. The vulnerability aligns with CWE-276, which specifically addresses incorrect permissions, and represents a clear violation of the principle of least privilege as outlined in the MITRE ATT&CK framework under privilege escalation techniques. Additional defensive measures should include implementing proper file system monitoring to detect unauthorized permission changes and ensuring that system updates are applied promptly to prevent exploitation of known vulnerabilities in system components.