Horizon Alert
Summary of the vulnerability and why it matters
A vulnerability in the GNU C Library could allow an attacker to cause a denial of service or potentially execute code on affected systems. This issue arises from a buffer overflow in a deprecated function that handles hostnames without proper length validation. The primary concern is confirming if this specific function is used within our environment, as its exposure is dependent on application implementation.
- Flaw in core library may allow code execution.
- Check if this specific deprecated function is used.
- Confirm relevance and exposure for our systems.
Attack Path
How an attacker could exploit the issue
An attacker could target a system by sending a specially crafted hostname to the deprecated `clnt_create` function within the GNU C Library's sunrpc module. This function, which handles network connections, copies the hostname argument onto the stack without checking its size. If the hostname is too long, it can overflow the buffer, potentially allowing an attacker to execute arbitrary code or cause a denial of service.
- No authentication or user interaction required.
- Triggered by passing a long hostname.
- Allows code execution or denial of service.
Live Threat
Current exploitation, exposure, and threat context
A buffer overflow in a deprecated GNU C Library function could allow an attacker to disrupt service or potentially execute arbitrary code. This could occur when the function's hostname argument is not properly validated, leading to memory corruption. The impact is dependent on whether applications using this function are compiled with stack protection.
- System data may be corrupted.
- Invalid hostname arguments could trigger overflow.
- Service disruption or code execution may occur.
Operational Fix
Recommended remediation, mitigation, and detection steps
This vulnerability in the GNU C Library's `clnt_create` function requires identifying which teams manage applications or systems utilizing this deprecated component. The initial step involves inventorying all deployments, verifying network exposure and business criticality, and then assigning ownership for remediation planning.
- Confirm application and infrastructure ownership.
- Verify direct network exposure and criticality.
- Plan remediation based on risk assessment.
