CVE-2019-9930 in Lexmark
Summary
by MITRE
Various Lexmark products have an Integer Overflow.
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Analysis
by VulDB Data Team • 08/08/2020
The vulnerability identified as CVE-2019-9930 represents a critical integer overflow flaw affecting multiple Lexmark printing devices and multifunctional systems. This issue stems from improper input validation within the device firmware where integer variables fail to properly handle values that exceed their maximum capacity. The flaw manifests when the system processes user-supplied data or network requests that contain maliciously crafted integer values. Integer overflows occur when arithmetic operations produce results that exceed the maximum value that can be stored in the allocated memory space, leading to unpredictable behavior and potential system compromise.
The technical implementation of this vulnerability involves the manipulation of integer variables used for buffer sizing, loop counters, or memory allocation parameters within Lexmark's embedded operating systems. When an attacker crafts input data that causes these integers to overflow, the system may allocate insufficient memory for operations or execute code in unintended memory locations. This particular flaw falls under the CWE-190 category of Integer Overflow or Wraparound, which is classified as a common weakness in software design that frequently leads to buffer overflows and memory corruption issues. The vulnerability exists in the device's network protocol handling components where incoming data packets are processed without adequate bounds checking.
From an operational standpoint, this vulnerability presents significant risk to enterprise environments relying on Lexmark devices for document management and printing services. Attackers could exploit this weakness to execute arbitrary code on affected devices, potentially gaining unauthorized access to sensitive network resources or compromising the entire print infrastructure. The impact extends beyond individual device compromise as networked printing systems often serve as entry points for broader lateral movement within corporate networks. This vulnerability aligns with ATT&CK technique T1071.004 for Application Layer Protocol: DNS and T1068 for Exploitation for Privilege Escalation, as it enables initial access and subsequent system compromise through malformed network traffic processing.
Organizations should implement immediate mitigation strategies including firmware updates from Lexmark to address the integer overflow issue, network segmentation to isolate affected printing devices, and enhanced monitoring of network traffic for suspicious patterns. The recommended approach involves deploying network access control lists to restrict communication with affected devices and implementing intrusion detection systems to monitor for exploitation attempts. Security teams should also conduct thorough vulnerability assessments of all networked printing infrastructure and establish incident response procedures specifically addressing printer device compromises. Regular firmware updates and patch management processes should be prioritized to prevent similar vulnerabilities from emerging in future device versions.