CVE-2021-1592 is a medium severity vulnerability found in Cisco Unified Computing System (UCS) Manager software. This vulnerability allows an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The root cause of this vulnerability lies in improper resource management for established SSH sessions. An attacker with valid user credentials could exploit this vulnerability by opening a significant number of SSH sessions, leading to a crash and restart of internal Cisco UCS Manager software processes.
The vulnerability was published on August 25, 2021, and has a CVSS score of 4.3, categorizing it as medium severity. The urgency for organizations to address this vulnerability is high due to the potential for service disruption, as affected devices may experience a temporary loss of access to the Cisco UCS Manager command-line interface (CLI) and web user interface (UI).
Organizations that are using the affected Cisco UCS Manager software are strongly advised to prioritize patching to mitigate the risks associated with this vulnerability. The attacker must have valid credentials, but the ability to exploit this flaw could lead to significant operational impacts.
Currently, there are no known public exploits or proofs of concept available for this vulnerability. However, the potential for exploitation remains, and the status of the vulnerability has been marked as modified, indicating that further developments may occur.
Vulnerability Details
CVE-2021-1592 is identified as a vulnerability related to improper resource management that affects the Cisco UCS Manager software. The official CVE description explains that an authenticated attacker could exploit this vulnerability to open excessive SSH sessions, which would lead to a denial of service.
The vulnerability has a CVSS 3.1 score of 4.3, indicating a medium severity. The attack vector is classified as NETWORK, requiring low attack complexity and low privileges. There is no user interaction needed for this vulnerability to be exploited, and it impacts availability.
Technical Analysis
The root cause of CVE-2021-1592 is improper resource management in the Cisco UCS Manager software regarding established SSH sessions. When an attacker opens a large number of SSH sessions, it can overwhelm the system resources, leading to a crash of the UCS Manager software processes. The attack complexity is low, as it does not require advanced skills, and the attacker only needs valid credentials to initiate the attack.
In terms of impacts, the vulnerability affects availability, as it can lead to a temporary denial of service. There is no confidentiality or integrity impact associated with this vulnerability. Organizations should assess their internal security policies and user credential management to mitigate potential risks.
Risk & Impact Analysis
The risk to organizations includes potential downtime of critical services managed by Cisco UCS Manager. Given the nature of the vulnerability, organizations with exposed interfaces may be at higher risk if attackers gain access to valid user credentials. The availability impact is categorized as low; however, any service disruption can affect business operations, particularly in environments where uptime is crucial.
Organizations should therefore address the vulnerability in their priority patch cycle. The urgency is further supported by the CVSS score of 4.3. Regular audits of user credentials and access controls are recommended to minimize the chances of exploitation.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of Cisco Unified Computing System include versions from 4.0 to 4.0(4m) and from 4.1 to 4.1(3e). Users should verify their current version against Cisco's advisory to determine if they are at risk.
Mitigation & Remediation
Cisco has released patches to address this vulnerability. Organizations should ensure they are running the latest version of Cisco UCS Manager software. More information on remediation can be found in the official vendor advisory. Additionally, organizations should review their SSH session configurations and implement rate limiting to prevent the opening of excessive sessions.
Detection Guidance
Monitoring SSH session logs for unusual activity can provide early indications of attempts to exploit this vulnerability. Organizations should look for patterns of multiple SSH session initiations from a single user or IP address, which could indicate an active attack.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-1592 lies in its demonstration of the risks associated with resource management in networked systems. As attackers continue to explore ways to disrupt services, this vulnerability highlights the importance of robust configurations and monitoring.
Security teams can learn from this incident by prioritizing the management of SSH sessions and ensuring that access controls are stringent. Furthermore, continuous security assessments can help identify similar vulnerabilities in other systems before they can be exploited.
Organizations should consider implementing application security assessments and regular penetration testing to mitigate similar risks in the future.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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