CVE-2011-2198 in openSUSE
Summary
by MITRE
The "insert-blank-characters" capability in caps.c in gnome-terminal (vte) before 0.28.1 allows remote authenticated users to cause a denial of service (CPU and memory consumption and crash) via a crafted file, as demonstrated by a file containing the string, "\033[100000000000000000@".
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Analysis
by VulDB Data Team • 12/02/2024
The vulnerability identified as CVE-2011-2198 affects the gnome-terminal application through its VTE (Virtual Terminal Emulator) component, specifically within the caps.c file. This issue represents a classic denial of service vulnerability that exploits how the terminal emulator processes certain character sequences. The flaw manifests when the application encounters a crafted input string containing the sequence "[100000000000000000@" which triggers the insertion of blank characters functionality. The vulnerability exists in versions prior to 0.28.1 of the VTE library, making it a significant concern for systems running older versions of gnome-terminal or applications that depend on this terminal emulator component.
The technical mechanism behind this vulnerability involves the improper handling of escape sequences in terminal emulators. When the VTE component processes the crafted escape sequence, it interprets the large numerical value following the control sequence as a request to insert an enormous number of blank characters. This creates a massive memory allocation request that consumes excessive CPU resources and memory. The vulnerability operates at the terminal emulation level where control characters and escape sequences are parsed and executed, making it particularly dangerous as it can be triggered through normal file operations or text processing. The flaw demonstrates poor input validation and resource management within the terminal emulator's parsing logic, leading to unbounded resource consumption.
From an operational perspective, this vulnerability enables authenticated remote attackers to cause significant system disruption by consuming all available CPU cycles and memory resources on the affected system. The impact extends beyond simple service interruption to potentially causing system instability or crashes, particularly in environments where gnome-terminal is frequently used or where multiple instances might be running simultaneously. The vulnerability is particularly concerning because it can be triggered through seemingly innocuous text files, making it difficult to detect and prevent through traditional security measures. This type of attack can be used to exhaust system resources, potentially leading to denial of service for legitimate users or applications running on the same system.
The mitigation strategy for CVE-2011-2198 involves immediate upgrading to VTE version 0.28.1 or later, which includes proper bounds checking and resource management for escape sequence processing. Organizations should also implement input validation measures at network boundaries and consider deploying terminal emulator sandboxes or containers to isolate vulnerable applications. System administrators should monitor for unusual CPU and memory consumption patterns that might indicate exploitation attempts. This vulnerability aligns with CWE-704 (Improper Control of Resource Identifiers) and can be mapped to ATT&CK technique T1499.004 (Endpoint Denial of Service) in threat modeling contexts. Regular security assessments and vulnerability scanning should include checks for outdated VTE components, particularly in enterprise environments where gnome-terminal or related applications are in use, as the vulnerability affects a core system component with wide-ranging deployment across Linux desktop and server environments.