CVE-2017-10850 in Driver for ApeosPort-VI
Summary
by MITRE
Untrusted search path vulnerability in Installers of ART EX Driver for ApeosPort-VI C7771/C6671/C5571/C4471/C3371/C2271, DocuCentre-VI C7771/C6671/C5571/C4471/C3371/C2271 (Timestamp of code signing is before 12 Apr 2017 02:04 UTC.), PostScript? Driver + Additional Feature Plug-in + PPD File for ApeosPort-VI C7771/C6671/C5571/C4471/C3371/C2271, DocuCentre-VI C7771/C6671/C5571/C4471/C3371/C2271 (Timestamp of code signing is before 12 Apr 2017 02:10 UTC.), XPS Print Driver for ApeosPort-VI C7771/C6671/C5571/C4471/C3371/C2271, DocuCentre-VI C7771/C6671/C5571/C4471/C3371/C2271 (Timestamp of code signing is before 3 Nov 2017 23:48 UTC.), ART EX Direct FAX Driver for ApeosPort-VI C7771/C6671/C5571/C4471/C3371/C2271, DocuCentre-VI C7771/C6671/C5571/C4471/C3371/C2271 (Timestamp of code signing is before 26 May 2017 07:44 UTC.), Setting Restore Tool for ApeosPort-VI C7771/C6671/C5571/C4471/C3371/C2271, DocuCentre-VI C7771/C6671/C5571/C4471/C3371/C2271 (Timestamp of code signing is before 25 Aug 2015 08:51 UTC.) allows an attacker to gain privileges via a Trojan horse DLL in an unspecified directory.
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Analysis
by VulDB Data Team • 11/12/2019
This vulnerability represents a classic untrusted search path issue affecting multiple printer driver installers for Kyocera ApeosPort-VI and DocuCentre-VI series devices. The flaw manifests in the installation processes where the software fails to properly validate or sanitize the search paths used to locate required dynamic link libraries. This weakness allows attackers to place malicious DLL files in directories that are searched before legitimate system locations, enabling privilege escalation through Trojan horse techniques. The vulnerability affects various driver components including PostScript drivers, XPS print drivers, and fax drivers, all of which were signed with timestamps predating the respective security awareness periods, indicating these issues were present in older software versions that may not have received adequate security updates.
The technical implementation of this vulnerability stems from improper path resolution mechanisms within the installer executables. When the installation process executes, it searches for required DLL dependencies in a predetermined order that includes user-writable directories, allowing attackers to place malicious libraries that will be loaded instead of legitimate ones. This behavior aligns with CWE-427 Uncontrolled Search Path Element, which specifically addresses situations where applications search for libraries in directories that can be manipulated by unprivileged users. The vulnerability exists because the installers do not implement proper security controls to ensure that only trusted libraries are loaded, creating an opportunity for attackers to execute arbitrary code with elevated privileges during the installation process.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and persistent malicious presence. Attackers exploiting this weakness could install backdoors, keyloggers, or other malicious software that persists even after system reboots. The vulnerability affects multiple device models across different driver categories, indicating a systemic issue in the software development lifecycle where search path validation was not properly implemented across the entire product line. This presents significant risk for enterprise environments where these printers are commonly deployed and may be managed through centralized print server configurations, allowing attackers to compromise entire network printer infrastructures. The timing of the code signing certificates, particularly those predating 2017, suggests that these vulnerable components were in widespread use for extended periods without proper security hardening.
Mitigation strategies for this vulnerability require both immediate and long-term approaches to address the root cause. System administrators should immediately verify that all affected printer drivers are updated to versions that properly implement secure search path resolution, ensuring that installers do not search in user-writable directories for critical libraries. The recommended solution involves implementing proper DLL search path validation by using the LoadLibraryEx function with the LOAD_LIBRARY_AS_DATAFILE flag or by explicitly specifying full paths to trusted libraries. Organizations should also consider implementing application whitelisting policies that prevent execution of unsigned or untrusted DLL files in system directories, leveraging technologies such as Windows AppLocker or similar endpoint protection solutions. Additionally, network segmentation and monitoring should be enhanced to detect unauthorized installation activities on printer management systems, as this vulnerability could be exploited to establish persistent access points within network environments. The remediation process should include comprehensive vulnerability scanning to identify all affected devices and ensure that updated drivers are properly deployed across all networked printer systems.