CVE-2021-26829 is a stored cross-site scripting (XSS) vulnerability affecting OpenPLC ScadaBR. Specifically, it affects versions through 0.9.1 on Linux and through 1.12.4 on Windows. This vulnerability allows attackers to inject malicious scripts via the system_settings.shtm file, potentially compromising the integrity of the application and the data it handles.
The CVSS score for this vulnerability is 5.4, categorizing it as medium severity. This rating signifies a moderate risk to organizations, particularly those utilizing ScadaBR in critical environments, where the integrity of operational data is paramount. The attack vector is network-based, requiring low complexity and minimal privileges, but necessitating user interaction, which may increase the likelihood of successful exploitation.
Given the potential impact of this vulnerability, including the ability for unauthorized users to manipulate application behavior, organizations are urged to address this issue promptly. The urgency for defenders is underscored by its inclusion in the Known Exploited Vulnerabilities (KEV) catalog, indicating a recognized threat landscape.
Organizations should prioritize patching immediately, applying necessary mitigations as outlined in vendor advisories to secure their systems against potential attacks leveraging this vulnerability.
Vulnerability Details
The vulnerability is classified as a stored XSS, a common attack vector where an attacker injects malicious scripts that are then executed by unsuspecting users. The official description states that OpenPLC ScadaBR, through version 0.9.1 on Linux and 1.12.4 on Windows, allows for this type of injection via the system_settings.shtm file.
The CVSS 3.1 score of 5.4 indicates a medium severity level, with the attack vector being network-based, requiring low complexity and low privileges from the attacker, along with user interaction for successful exploitation. The vulnerability impacts integrity and confidentiality, while availability remains unaffected.
Technical Analysis
The root cause of this vulnerability lies in inadequate validation of user input, leading to the possibility of executing arbitrary scripts in the context of the user's browser session. The attack vector is network-based, meaning that an attacker can exploit this vulnerability remotely. The attack complexity is low, and the attacker requires only low privileges to initiate this attack.
User interaction is required, which means that a victim must be tricked into clicking a malicious link or visiting a compromised page. The impact on confidentiality and integrity is low, indicating that while data may be manipulated or exposed, it is not completely compromised. Availability is not affected by this vulnerability.
Risk & Impact Analysis
The real-world deployment risk associated with CVE-2021-26829 is significant, especially for organizations operating in environments where ScadaBR is utilized for critical operations. Attackers may leverage this vulnerability to execute malicious scripts, leading to unauthorized access to sensitive data or system functionalities.
Risk to organizations includes potential data theft, manipulation of critical operational parameters, or even broader impacts on organizational integrity if the system is compromised. The blast radius is considerable, as this vulnerability could be exploited to affect multiple users and systems if not adequately addressed.
Given the CVSS score and the vulnerability's inclusion in the KEV catalog, organizations should schedule remediation as part of their priority patch cycle to mitigate risks adequately.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
The vulnerability affects OpenPLC ScadaBR versions through 0.9.1 on Linux and through 1.12.4 on Windows. Organizations using these versions should take immediate action to remediate this vulnerability.
Mitigation & Remediation
Organizations should apply the latest patches provided by the vendor to mitigate this vulnerability. If an immediate patch is not available, consider implementing workarounds such as input validation and sanitization to reduce the risk of exploitation.
For comprehensive security, organizations may also consider undergoing a penetration testing service to identify potential weaknesses in their systems.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor application logs for unusual activity, such as unexpected user inputs or script execution errors. Additionally, behavioral anomalies in user interactions should be investigated.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-26829 underscores the need for ongoing vigilance in securing web applications against XSS vulnerabilities. This incident highlights the importance of regular security assessments and proactive measures to mitigate risks.
Security teams should remain aware of emerging threats associated with similar vulnerabilities and invest in training to recognize potential exploitation techniques. For further insights into securing your applications, consider reviewing our web application penetration testing strategies.
Additionally, organizations should consider implementing comprehensive security frameworks to address these vulnerabilities effectively, as discussed in our penetration testing methodology guide.
Finally, remain engaged with security communities and resources to stay informed on the latest trends and best practices in application security. Explore our vulnerability management program design strategies for more insights.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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