How CVE-2025-2581 Works
The vulnerability in xmedcon 0.25.0 stems from an integer underflow in the `malloc` function within the DICOM file handler component. When processing specially crafted DICOM files, improper size calculations during memory allocation lead to an integer underflow, causing insufficient memory allocation. Attackers can exploit this remotely by sending malicious DICOM files, potentially resulting in heap corruption, crashes, or arbitrary code execution. The flaw is triggered during file parsing when unchecked arithmetic operations reduce the requested memory size below zero, which is then interpreted as an extremely large value.
DailyCVE Form
Platform: xmedcon
Version: 0.25.0
Vulnerability: Integer Underflow
Severity: Medium
Date: 03/27/2025
What Undercode Say:
Exploitation Analysis
- Craft a malformed DICOM file with manipulated metadata fields.
- Trigger the underflow by forcing a negative size calculation.
- Overflow the undersized heap buffer to gain control.
Protection Measures
1. Update to xmedcon 0.25.1 immediately.
2. Validate DICOM file metadata before processing.
3. Implement bounds checking for memory allocations.
Detection Commands
Check installed xmedcon version dpkg -l | grep xmedcon Scan for vulnerable DICOM parsers strings /usr/bin/xmedcon | grep "DICOM_handler"
Exploit Code Snippet (PoC)
include <stdio.h>
include <stdlib.h>
void craft_malicious_dicom() {
uint32_t malicious_size = 0xFFFFFFF0;
// Manipulate DICOM header to trigger underflow
write_dicom_tag("AllocSize", malicious_size);
}
Mitigation Script
!/bin/sh Force upgrade xmedcon apt-get update && apt-get install xmedcon=0.25.1-1
Network Protections
1. Block suspicious DICOM files at the firewall:
iptables -A INPUT -p tcp --dport 104 -m string --hex-string "|FF FF FF F0|" -j DROP
Debugging
Use Valgrind to detect heap corruption:
valgrind --tool=memcheck xmedcon malicious.dcm
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-2581
Extra Source Hub:
Undercode
