CVE-2025-24928 is a stack-based buffer overflow vulnerability identified in the widely used XML parsing library libxml2, specifically in the xmlSnprintfElements function located in valid.c. This vulnerability affects libxml2 versions prior to 2.12.10 and 2.13.x versions before 2.13.6. The flaw arises during Document Type Definition (DTD) validation when processing XML documents or DTDs that are untrusted. Exploitation requires that the vulnerable application perform DTD validation on maliciously crafted XML input, which triggers the buffer overflow condition. This can lead to corruption of the stack, potentially allowing an attacker to execute arbitrary code or cause denial of service by crashing the application. The vulnerability is similar to CVE-2017-9047, indicating a recurring issue in the handling of DTD validation in libxml2. According to the CVSS v3.1 vector, the attack requires local access (AV:L), has high attack complexity (AC:H), does not require privileges (PR:N), nor user interaction (UI:N), and impacts confidentiality and integrity with a scope change (S:C). No public exploits have been reported yet, but the high severity score of 7.8 underscores the criticality of patching. The vulnerability is particularly relevant for software and services that parse XML data with DTD validation enabled, especially when processing untrusted or external XML inputs. Since libxml2 is embedded in numerous open-source and commercial applications, the attack surface is broad. The vulnerability's exploitation could lead to unauthorized data disclosure, code execution, or system compromise.

For European organizations, the impact of CVE-2025-24928 can be significant, particularly for those relying on software that uses libxml2 for XML parsing with DTD validation enabled. Industries such as finance, telecommunications, healthcare, and critical infrastructure often process XML data and may be exposed if untrusted XML inputs are validated. Exploitation could lead to unauthorized access to sensitive data, disruption of services, or full system compromise, undermining confidentiality and integrity. Given the high CVSS score and scope change, the vulnerability could affect multiple components within an organization’s IT environment. The requirement for local access and high attack complexity somewhat limits remote exploitation but does not eliminate risk, especially in multi-tenant or shared environments where local access might be easier to obtain. The absence of known exploits in the wild currently reduces immediate risk but does not preclude future attacks. European organizations must consider the potential for targeted attacks leveraging this vulnerability, especially in sectors with high-value data or critical operations.

1. Immediately upgrade libxml2 to version 2.12.10 or 2.13.6 or later, where the vulnerability is patched. 2. Audit all applications and services that utilize libxml2 to identify those performing DTD validation on XML inputs, especially from untrusted sources. 3. Disable DTD validation where it is not strictly necessary, or implement strict input validation and sanitization to prevent malicious XML payloads. 4. Employ application-layer firewalls or XML gateways that can detect and block malicious XML content before it reaches vulnerable parsers. 5. Monitor logs and system behavior for signs of exploitation attempts, such as crashes or anomalous process activity related to XML processing. 6. Educate developers and system administrators about the risks of processing untrusted XML with DTD validation enabled and encourage secure coding practices. 7. For environments where local access is possible by untrusted users, enforce strict access controls and segmentation to reduce the risk of exploitation. 8. Stay informed about any emerging exploits or patches related to this vulnerability.