Overview
The cybersecurity landscape is witnessing a new vulnerability that poses a significant threat to the data integrity and system security of numerous devices and applications. The vulnerability, identified as CVE-2025-50518, affects the libcoap library, widely used in embedded systems and IoT devices for the Constrained Application Protocol (CoAP). This vulnerability can lead to severe outcomes, including potential system compromise and data leakage. Given the ubiquitous use of libcoap in a range of devices, the implications of this vulnerability are far-reaching and demand immediate attention.
Vulnerability Summary
CVE ID: CVE-2025-50518
Severity: Critical (9.8 CVSS Score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise, data leakage
Affected Products
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Product | Affected Versions
libcoap | All versions prior to patch
How the Exploit Works
The exploit leverages a use-after-free vulnerability in the coap_delete_pdu_lkd function within the coap_pdu.c file of the libcoap library. This vulnerability arises due to the improper handling of memory after the freeing of a Protocol Data Unit (PDU) object.
An attacker can manipulate this vulnerability by creating a malicious payload that causes the system to access the free memory space associated with the PDU object. This action can lead to memory corruption or even the execution of arbitrary code, paving the way for a potential system compromise or data leakage.
Conceptual Example Code
The following is a conceptual example of how the vulnerability might be exploited. It’s important to note that this is a conceptual example and not actual exploit code.
#include <coap.h>
...
coap_pdu_t *pdu;
pdu = coap_new_pdu(session);
...
// Malicious function that exploits the use-after-free vulnerability
void exploit(coap_pdu_t *pdu) {
coap_delete_pdu(session, pdu); // Free the pdu
// Perform an operation on the freed pdu, causing use-after-free
unsigned char *data = pdu->data;
}
...
exploit(pdu);Mitigation Guidance
Users are strongly advised to apply the vendor patch as soon as possible for the most effective mitigation. In the interim, employing a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation strategy. These tools can help detect and prevent attempts to exploit the vulnerability. However, these are not foolproof solutions and do not substitute the need for applying the vendor patch.