CVE-2026-103590 in QloApps
Summary
by MITRE • 10/01/2026
QloApps through 1.7.0 contains a reflected cross-site scripting vulnerability in the back-office room type editor's length of stay fields. Attackers can induce authenticated administrators to submit crafted POST requests with malicious payloads in restriction_min_los and restriction_max_los parameters, executing arbitrary JavaScript in the victim's administrative session.
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Analysis
by VulDB Data Team • 10/01/2026
The identified security flaw resides within QloApps versions up to 1.7.0, specifically targeting the back-office room type editor functionality. This vulnerability is classified as a reflected cross-site scripting (XSS) issue that affects critical administrative interfaces used for managing hotel or accommodation booking parameters. The core technical deficiency lies in the insufficient sanitization and validation of input data within the length of stay configuration fields. When an authenticated administrator interacts with this module to define minimum and maximum lengths of stay, the application fails to properly encode or filter special characters before rendering them back into the HTML response context. This lack of proper output encoding allows malicious scripts embedded in user-supplied input to be executed directly by the victim's web browser during the administrative session.
The exploitation vector for this vulnerability involves crafted HTTP POST requests directed at specific endpoints handling room type restrictions. An attacker can induce a targeted administrator, who is already authenticated and logged into the QloApps back-office, to submit these malicious payloads via parameters named restriction_min_los and restriction_max_los. These parameters are intended to accept numeric values representing days or nights but do not enforce strict data typing on the server side before reflection occurs in subsequent responses. By embedding JavaScript code within these fields, an attacker can trigger execution when the administrator views the edited room type configuration. This mechanism relies heavily on social engineering tactics to lure privileged users into interacting with manipulated URLs or forms controlled by the adversary.
The operational impact of this vulnerability is severe due to the high privilege level of the target audience. Since the attack targets administrative accounts, successful exploitation grants an attacker full control over the application's backend functionality. This includes the ability to steal session cookies and authentication tokens, which can lead to complete account takeover. Furthermore, attackers can perform actions on behalf of the administrator, such as modifying booking rules, accessing sensitive customer data, or injecting persistent malware into the system interface. The reflected nature of this XSS means that each attack requires a separate interaction from the victim, but it allows for precise targeting and potentially bypasses certain browser-based security filters if combined with other techniques like clickjacking or phishing campaigns.
From a classification perspective, this vulnerability aligns with CWE-79, which describes Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. The specific context involves reflected XSS where the malicious payload is sent via POST requests and immediately returned in the HTTP response without adequate sanitization. In terms of offensive security frameworks, this behavior maps to MITRE ATT&CK technique T1059, specifically sub-technique 007 for JavaScript execution within web browsers. It also relates to TA0003 Persistence if session hijacking leads to long-term access or TA0005 Defense Evasion if the attacker uses obfuscation techniques in their payloads.
Mitigation strategies should focus on both immediate remediation and long-term defensive coding practices. The primary fix requires implementing strict input validation that rejects any non-numeric characters for length of stay fields, ensuring only integers are accepted by the backend logic. Additionally, output encoding must be applied consistently across all administrative views to prevent script injection even if future inputs slip through validation layers. Developers should adopt a whitelist approach for allowed characters rather than relying on blacklist filters which can often be bypassed using encoding tricks or alternative character sets. Upgrading QloApps to version 1.7.1 or later is recommended as it addresses these specific input handling deficiencies in the room type editor module.