CVE-2024-12084: Samba Rsync Buffer Overflow Vulnerability

CVE-2024-12084 Overview

A heap-based buffer overflow flaw was found in the rsync daemon. This issue is due to improper handling of attacker-controlled checksum lengths (s2length) in the code. When MAX_DIGEST_LEN exceeds the fixed SUM_LENGTH (16 bytes), an attacker can write out of bounds in the sum2 buffer.

Critical Impact
This vulnerability could allow an unauthenticated attacker to execute arbitrary code remotely, potentially taking control of affected systems.

Affected Products

samba rsync
almalinux almalinux
archlinux arch_linux
gentoo linux

Discovery Timeline

2025-01-15 - CVE CVE-2024-12084 published to NVD
2025-11-03 - Last updated in NVD database

Technical Details for CVE-2024-12084

Vulnerability Analysis

The vulnerability occurs due to a heap-based buffer overflow in the rsync daemon. It arises when the length of the checksum sent by an attacker exceeds the predefined limit, leading to out-of-bounds writes.

Root Cause

Improper handling of checksum lengths, leading to buffer overflow when MAX_DIGEST_LEN is greater than SUM_LENGTH.

Attack Vector

This vulnerability can be exploited over the network by sending a specially crafted request to the affected rsync daemon.

// Example exploitation code (sanitized)
void vulnerable_function(char* input) {
    char sum2[16];
    unsigned int length = strlen(input);
    if (length > 16) {
        // Improper length handling
        memcpy(sum2, input, length);
    }
}

Detection Methods for CVE-2024-12084

Indicators of Compromise

Unexpected rsync daemon crashes
Unusual network activity to rsync ports
Presence of unauthorized checksum length values

Detection Strategies

Monitor network traffic for abnormal patterns targeting rsync services. Analyze logs for unexpected crashes or errors indicating exploitation attempts.

Monitoring Recommendations

Utilize SentinelOne's behavioral AI to identify and block exploitation attempts in real-time, ensuring seamless protection against anomalous activities targeting the rsync service.

How to Mitigate CVE-2024-12084

Immediate Actions Required

Disable rsync services if not in use
Limit network access to rsync ports
Apply available patches from vendors

Patch Information

Patches addressing this issue have been released by affected vendors. Ensure to apply these patches to mitigate the vulnerability.

Workarounds

Until patches are applied, consider using firewalls to block untrusted networks from accessing rsync services.

bash

# Configuration example to block access
iptables -A INPUT -p tcp --dport 873 -j DROP