CVE-2021-20868: Medium Vulnerability in KONICA MINOLTA bizhub Series

The vulnerability identified as CVE-2021-20868 is categorized as an incorrect authorization flaw affecting various models in the KONICA MINOLTA bizhub series. This vulnerability allows an attacker on the adjacent network to obtain user credentials if external server authentication is enabled via a specific SOAP message sent by an administrative user.

With a CVSS score of 4.5, this vulnerability is classified as medium severity. The implications of this vulnerability are significant, as unauthorized access could lead to compromised user accounts and sensitive information exposure.

Organizations utilizing affected models should be aware of the risk to their operational integrity and take necessary steps to mitigate this vulnerability. The presence of this vulnerability indicates a real-world risk, particularly in environments where administrative access is shared or poorly controlled.

Current exploitation status indicates that there are no known public exploits or proof of concept available. However, the nature of the vulnerability and its exploitation potential necessitate that organizations prioritize patching and remediation efforts.

Organizations should prioritize patching immediately.

Vulnerability Details

The official description of this vulnerability is as follows: Incorrect authorization vulnerability in KONICA MINOLTA bizhub series (bizhub C750i G00-35 and earlier, bizhub C650i/C550i/C450i G00-B6 and earlier, bizhub C360i/C300i/C250i G00-B6 and earlier, bizhub 750i/650i/550i/450i G00-37 and earlier, bizhub 360i/300i G00-33 and earlier, bizhub C287i/C257i/C227i G00-19 and earlier, bizhub 306i/266i/246i/226i G00-B6 and earlier, bizhub C759/C659 GC7-X8 and earlier, bizhub C658/C558/C458 GC7-X8 and earlier, bizhub 958/808/758 GC7-X8 and earlier, bizhub 658e/558e/458e GC7-X8 and earlier, bizhub C287/C227 GC7-X8 and earlier, bizhub 287/227 GC7-X8 and earlier, bizhub 368e/308e GC7-X8 and earlier, bizhub C368/C308/C258 GC9-X4 and earlier, bizhub 558/458/368/308 GC9-X4 and earlier, bizhub C754e/C654e GDQ-M0 and earlier, bizhub 754e/654e GDQ-M0 and earlier, bizhub C554e/C454e GDQ-M1 and earlier, bizhub C364e/C284e/C224e GDQ-M1 and earlier, bizhub 554e/454e/364e/284e/224e GDQ-M1 and earlier, bizhub C754/C654 C554/C454 GR1-M0 and earlier, bizhub C364/C284/C224 GR1-M0 and earlier, bizhub 754/654 GR1-M0 and earlier, bizhub C4050i/C3350i/C4000i/C3300i G00-B6 and earlier, bizhub C3320i G00-B6 and earlier, bizhub 4750i/4050i G00-22 and earlier, bizhub 4700i G00-22 and earlier, bizhub C3851FS/C3851/C3351 GC9-X4 and earlier, and bizhub 4752/4052 GC9-X4 and earlier) allows an attacker on the adjacent network to obtain user credentials if external server authentication is enabled via a specific SOAP message sent by an administrative user.

The vulnerability is classified under the Common Weakness Enumeration (CWE) as CWE-863, indicating issues with authorization.

Technical Analysis

The root cause of this vulnerability stems from incorrect authorization mechanisms in the firmware of various models within the KONICA MINOLTA bizhub series. This flaw allows attackers to send specially crafted SOAP messages that can bypass authentication checks, enabling unauthorized access to user credentials.

The attack vector is classified as adjacent network, meaning that an attacker must be on the same local network as the target device. The attack complexity is rated as low, with high privileges required for successful exploitation.

No user interaction is necessary for this exploit, as the SOAP message can be sent directly by the attacker. The impact on confidentiality is high, as successful exploitation can lead to the disclosure of user credentials. However, integrity and availability impacts are rated as none.

Risk & Impact Analysis

The real-world deployment risk associated with CVE-2021-20868 is significant. Organizations should recognize that an attacker could gain unauthorized access to sensitive information, especially in environments where administrative access is poorly controlled or shared among users. This vulnerability highlights the necessity for robust access controls and monitoring mechanisms.

Given the CVSS score of 4.5 and the absence of known exploits, organizations should still treat this vulnerability with urgency. While exploitation may not be actively occurring, the potential for impact remains high, especially if left unaddressed.

As part of a comprehensive security strategy, organizations should include this vulnerability in their risk assessments and prioritize remediation efforts accordingly.

Exploitation Status

Affected Versions

The affected versions include several models in the KONICA MINOLTA bizhub series, including but not limited to:

All versions prior to vendor patch.

Mitigation & Remediation

To remediate this vulnerability, organizations should ensure they apply the latest firmware updates from KONICA MINOLTA, which address this authorization issue. Specific model patches should be checked against the vendor's advisory, which can be found on their official site.

In the absence of immediate patches, organizations should implement strict network segmentation, ensuring that administrative interfaces are inaccessible from the public or adjacent networks.

For further guidance on penetration testing and assessing configurations, organizations can refer to penetration testing services to validate their defensive measures.

Detection Guidance

To detect potential exploitation attempts of this vulnerability, organizations should monitor logs for unusual SOAP message patterns and authentication failures, particularly from administrative interfaces.

Behavioral anomalies, such as failed logins or unexpected access requests, should also trigger alerts for further investigation.

AppSecure Threat Intelligence Insight

CVE-2021-20868 serves as a reminder of the critical importance of proper authorization mechanisms in networked devices. The trend of increasing vulnerabilities in multifunction printers and office equipment indicates a growing attack surface that organizations must address.

Security teams should consider conducting an application security assessment to identify and remediate similar vulnerabilities proactively.

In light of this vulnerability, organizations should also review their vulnerability management program to enhance their security posture.

Finally, organizations should remain vigilant and prepared to respond to emerging threats, ensuring that their security measures are robust and adaptive.