CVE-2022-23458 is a cross-site scripting (XSS) vulnerability affecting versions of the Toast UI Grid (tui.grid) component prior to 4.21.3. Toast UI Grid is a JavaScript-based data grid component used to display and edit tabular data within web applications. The vulnerability arises when a user pastes specially crafted content into editable cells of the grid. Due to insufficient input sanitization or output encoding, malicious scripts embedded in the pasted content can be executed in the context of the web application. This allows an attacker to execute arbitrary JavaScript code within the victim's browser session. The vulnerability is classified under CWE-79, which covers improper neutralization of input during web page generation leading to XSS attacks. The issue was addressed and fixed in version 4.21.3 of tui.grid. No known workarounds exist, meaning that upgrading to the patched version is the primary remediation. There are no reports of active exploitation in the wild as of the published date. The vulnerability requires user interaction in the form of pasting data into the grid's editable cells, which means an attacker typically needs to trick a user into performing this action, for example via social engineering or malicious content delivery. The impact of successful exploitation includes the potential theft of session cookies, user credentials, or execution of actions on behalf of the user within the vulnerable web application, potentially leading to account compromise or data leakage. Since tui.grid is a front-end component, the vulnerability affects any web application that integrates the affected versions and exposes editable grid cells to users.

For European organizations, the impact of this vulnerability depends on the extent to which they use the vulnerable versions of tui.grid in their web applications, particularly those handling sensitive or regulated data. Exploitation could lead to unauthorized access to user accounts, data exfiltration, or manipulation of data displayed or entered via the grid component. This is especially critical for sectors such as finance, healthcare, government, and critical infrastructure where data integrity and confidentiality are paramount. The vulnerability could also undermine user trust and lead to regulatory compliance issues under GDPR if personal data is compromised. Since the attack requires user interaction, phishing or social engineering campaigns could be used to induce users to paste malicious content, increasing the risk in environments with less security awareness. The lack of known exploits in the wild reduces immediate risk but does not eliminate the threat, as attackers may develop exploits targeting vulnerable European web applications. The vulnerability's medium severity suggests moderate risk but should not be underestimated given the potential for targeted attacks against high-value organizations.

1. Immediate upgrade to tui.grid version 4.21.3 or later to ensure the vulnerability is patched. 2. Conduct an inventory of web applications using tui.grid to identify affected versions and prioritize patching. 3. Implement Content Security Policy (CSP) headers with strict script-src directives to limit the impact of potential XSS attacks. 4. Employ input validation and sanitization on the server side where possible to complement client-side fixes. 5. Educate users about the risks of pasting content from untrusted sources, especially in editable fields. 6. Monitor web application logs for unusual paste events or script execution anomalies. 7. For organizations unable to immediately upgrade, consider disabling editable cells or restricting paste functionality temporarily as a stopgap measure. 8. Integrate automated security testing in the development lifecycle to detect similar vulnerabilities proactively. 9. Review and strengthen phishing awareness programs to reduce the likelihood of successful social engineering attacks that could trigger exploitation.