CVE-2023-4554 is a vulnerability classified under CWE-611, indicating an Improper Restriction of XML External Entity (XXE) Reference in the OpenText AppBuilder product. This vulnerability affects versions from 21.2 up to but not including 23.2 on Windows and Linux platforms. The root cause lies in the XML processor used by AppBuilder, which does not adequately restrict the processing of external entities within XML files. An authenticated user can exploit this by uploading specially crafted XML files that trigger server-side request forgery (SSRF) and allow the attacker to probe and disclose sensitive local files on the server processing these XML inputs. The vulnerability requires authentication but no user interaction beyond that, and it does not impact integrity or availability directly but has a high impact on confidentiality due to potential exposure of sensitive server-side data. The CVSS v3.1 base score is 4.9 (medium severity), reflecting the network attack vector, low attack complexity, and the requirement for high privileges (authenticated user). No known exploits are currently reported in the wild, and no official patches are linked yet, indicating that organizations using affected versions should prioritize mitigation and monitoring. The vulnerability could be leveraged to gain intelligence about internal server configurations or sensitive files, potentially facilitating further attacks or data breaches.

For European organizations using OpenText AppBuilder versions 21.2 through before 23.2, this vulnerability poses a confidentiality risk by enabling authenticated users to access sensitive internal files and potentially internal network resources via SSRF. This could lead to unauthorized disclosure of intellectual property, personal data protected under GDPR, or internal system configurations. Given the medium severity and the requirement for authentication, the threat is more relevant to insider threats or compromised accounts rather than external unauthenticated attackers. However, if attackers gain access to valid credentials, they could exploit this vulnerability to escalate their reconnaissance capabilities and plan more damaging attacks. Organizations in sectors with strict data protection regulations, such as finance, healthcare, and government, could face compliance risks and reputational damage if sensitive data is exposed. The lack of known exploits suggests a window for proactive defense, but also means attackers may develop exploits in the near future.

1. Upgrade OpenText AppBuilder to version 23.2 or later once available, as this version is not affected. 2. Until patches are available, restrict access to AppBuilder to trusted and authenticated users only, enforcing strong authentication mechanisms such as multi-factor authentication (MFA). 3. Implement strict input validation and XML parser configurations that disable external entity processing (XXE) where possible, or use safer XML parsing libraries. 4. Monitor logs for unusual XML upload activities or SSRF patterns, including unexpected outbound requests from the AppBuilder server. 5. Employ network segmentation to limit the AppBuilder server’s ability to access sensitive internal resources or files beyond what is necessary. 6. Conduct regular audits of user privileges to minimize the number of users with access to upload XML files. 7. Prepare incident response plans specific to potential data disclosure incidents stemming from this vulnerability.