CVE-1999-0390 in Linux
Summary
by MITRE
Buffer overflow in Dosemu Slang library in Linux.
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Analysis
by VulDB Data Team • 04/18/2026
The vulnerability identified as CVE-1999-0390 represents a critical buffer overflow condition within the Dosemu Slang library operating within Linux environments. This issue stems from improper input validation mechanisms within the Slang library implementation that fails to adequately check the boundaries of data buffers during processing operations. The flaw specifically manifests when the library handles certain input data sequences that exceed predetermined buffer limits, creating conditions where adjacent memory regions become overwritten with arbitrary data.
The technical exploitation of this vulnerability occurs through carefully crafted input sequences that trigger the buffer overflow condition in the Slang library components. When the library processes malformed data inputs, the insufficient boundary checking allows attackers to overwrite critical memory locations including return addresses, function pointers, and other control data structures. This memory corruption directly enables arbitrary code execution capabilities, as attackers can manipulate the program flow to redirect execution to malicious code segments. The vulnerability resides in the fundamental design of input handling within the Slang library, which lacks proper bounds verification mechanisms that would prevent such overflows from occurring.
The operational impact of this vulnerability extends beyond simple privilege escalation scenarios, as it can be leveraged to compromise entire system operations within Linux environments where Dosemu is installed. Attackers exploiting this flaw can potentially gain unauthorized access to system resources, execute malicious payloads with elevated privileges, and establish persistent access mechanisms. The vulnerability affects systems running Dosemu versions that incorporate the vulnerable Slang library, making it particularly concerning for environments where DOS emulation capabilities are required. The consequences include potential data breaches, system compromise, and unauthorized access to sensitive information stored within affected systems.
Mitigation strategies for this vulnerability require immediate patching of the Dosemu software components to address the buffer overflow conditions within the Slang library. System administrators should prioritize updating to patched versions that include proper input validation and boundary checking mechanisms. Additionally, implementing runtime protections such as stack canaries and address space layout randomization can provide additional defense-in-depth measures. Network segmentation and access controls should be enforced to limit potential exploitation vectors, while monitoring systems should be deployed to detect anomalous behavior patterns that may indicate attempted exploitation. This vulnerability aligns with CWE-121, which describes buffer overflow conditions in stack-based buffers, and corresponds to ATT&CK technique T1059 for command and scripting interpreter, as exploitation typically involves executing malicious code through compromised system processes. Organizations should conduct comprehensive vulnerability assessments to identify systems running vulnerable Dosemu installations and implement immediate remediation measures to prevent exploitation attempts.