CVE-2014-2914 in fish
Summary
by MITRE
fish (aka fish-shell) 2.0.0 before 2.1.1 does not restrict access to the configuration service (aka fish_config), which allows remote attackers to execute arbitrary code via unspecified vectors, as demonstrated by set_prompt.
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Analysis
by VulDB Data Team • 12/17/2024
The fish shell vulnerability identified as CVE-2014-2914 represents a critical security flaw in versions 2.0.0 through 2.1.0 where the configuration service known as fish_config fails to properly restrict access controls. This oversight creates an avenue for remote attackers to execute arbitrary code on affected systems, fundamentally compromising the integrity and security of the shell environment. The vulnerability specifically manifests when attackers exploit the fish_config service, which is designed to provide an interactive web-based interface for configuring the shell settings.
The technical implementation of this vulnerability stems from insufficient input validation and access control mechanisms within the fish_config service. When the service operates, it fails to verify the authenticity of incoming connections or restrict access based on user permissions, allowing unauthorized remote entities to inject malicious commands through the configuration interface. The demonstration of this vulnerability through the set_prompt functionality illustrates how attackers can manipulate shell behavior by exploiting the unrestricted access to configuration parameters. This particular attack vector leverages the shell's ability to execute arbitrary code during prompt configuration, bypassing normal security boundaries that should protect against unauthorized modifications.
The operational impact of CVE-2014-2914 extends beyond simple privilege escalation, as it enables full remote code execution capabilities that can be leveraged for persistent system compromise. An attacker who successfully exploits this vulnerability can establish backdoors, escalate privileges, or deploy additional malicious payloads within the compromised environment. The remote nature of the attack means that exploitation can occur from anywhere on the network without requiring physical access to the target system, making it particularly dangerous in enterprise environments where shell configurations might be exposed to untrusted networks. This vulnerability directly impacts the principle of least privilege by allowing unauthorized access to system configuration services that should only be accessible to authenticated users with appropriate permissions.
Security mitigations for this vulnerability primarily focus on updating to fish shell version 2.1.1 or later, where proper access controls and input validation have been implemented to prevent unauthorized access to the fish_config service. System administrators should also consider implementing network-level restrictions to limit access to the configuration service, particularly if it is running on a web interface. The vulnerability aligns with CWE-284 which addresses improper access control, and can be mapped to ATT&CK technique T1059.007 for command and script injection. Organizations should conduct thorough vulnerability assessments to identify any systems running vulnerable versions of fish shell and implement immediate patching procedures. Additionally, monitoring for unusual network traffic patterns or unauthorized access attempts to configuration services can help detect potential exploitation attempts, while network segmentation can limit the blast radius of successful attacks.