CVE-2025-0665: Haxx Curl Use-After-Free Vulnerability

CVE-2025-0665 Overview

libcurl would wrongly close the same eventfd file descriptor twice when taking
down a connection channel after having completed a threaded name resolve.

Critical Impact
This vulnerability can be exploited remotely resulting in potential denial of service conditions or further exploits like remote code execution due to underlying resource misuse.

Affected Products

haxx curl
netapp bootstrap_os
netapp hci_compute_node

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to haxx
Not Available - CVE CVE-2025-0665 assigned
Not Available - haxx releases security patch
2025-02-05 - CVE CVE-2025-0665 published to NVD
2025-07-30 - Last updated in NVD database

Technical Details for CVE-2025-0665

Vulnerability Analysis

The vulnerability arises when libcurl closes an eventfd file descriptor twice, leading to improper resource management. This could result in unexpected behavior or system crashes, making systems running affected versions of libcurl vulnerable to potential disruption services.

Root Cause

The root cause is the mismanagement of file descriptors in the codebase, specifically closing the same eventfd descriptor twice.

Attack Vector

Network-based attacks can be leveraged to exploit this vulnerability, often requiring no prior authentication or more than nominal user interaction.

// Example exploitation code (sanitized)
int fd = eventfd(0, 0);
if (fd == -1) {
    perror("eventfd");
    exit(EXIT_FAILURE);
}
// Incorrectly closing the descriptor twice can lead to undefined behavior
close(fd);
// Vulnerability occurs here
close(fd);

Detection Methods for CVE-2025-0665

Indicators of Compromise

Unusual error logs related to eventfd operations
Unexpected process terminations
Repeated resource exhaustion alerts

Detection Strategies

Utilize monitoring tools to detect repeated close() operations on the same file descriptor. Additionally, track system logs for anomalies in process behavior following network communications relying on threaded name resolution.

Monitoring Recommendations

Employ comprehensive runtime protection via SentinelOne's cutting-edge behavioral AI to monitor and block unexpected system calls and resource operations indicative of potential exploit attempts on vulnerable libcurl instances.

How to Mitigate CVE-2025-0665

Immediate Actions Required

Update to the latest patch of curl as per vendor recommendations
Monitor network access logs for repeated or failed connection attempts
Restrict network access to services using vulnerable libcurl versions

Patch Information

Refer to the vendor's advisory for updates and security patches as available at curl's CVE advisory.

Workarounds

Implement stricter file descriptor management within your application until a patch can be applied. Consider isolating vulnerable processes into containers for enhanced security.

bash

# Example of isolating a process in a temporary container
docker run --rm -v /app:/app isolated-libcurl:latest