CVE-2001-0058 in CBOS
Summary
by MITRE
The Web interface to Cisco 600 routers running CBOS 2.4.1 and earlier allow remote attackers to cause a denial of service via a URL that does not end in a space character.
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Analysis
by VulDB Data Team • 05/12/2019
The vulnerability identified as CVE-2001-0058 represents a critical denial of service flaw within Cisco 600 routers operating with CBOS 2.4.1 and earlier versions. This issue specifically affects the web-based management interface that administrators use to configure and monitor router operations. The vulnerability stems from improper input validation within the web server component of the router's operating system, creating an exploitable condition that can be leveraged by remote attackers to disrupt network services. The flaw manifests when the web interface processes URLs that do not conclude with a space character, indicating a fundamental parsing error in how the router handles HTTP requests.
The technical implementation of this vulnerability demonstrates a classic buffer over-read condition where the web server fails to properly validate the termination of URL strings. When an attacker crafts a malicious URL that lacks the expected trailing space character, the router's web interface processes this malformed input in a manner that triggers an unexpected behavior leading to system instability. This type of vulnerability falls under CWE-129, which describes improper validation of length of input buffers, and more specifically aligns with CWE-125, indicating an out-of-bounds read condition. The vulnerability operates at the application layer of the network stack, making it particularly dangerous as it can be exploited from remote locations without requiring physical access or authentication credentials.
From an operational perspective, this vulnerability presents significant risk to network availability and business continuity. Attackers can exploit this flaw to render the router's management interface inaccessible, effectively cutting off administrative access to the device while potentially causing the router to become unresponsive or crash entirely. The impact extends beyond simple service disruption as it can lead to complete network outages if the affected router serves as a critical gateway or core device within the network infrastructure. This vulnerability particularly affects enterprise and service provider networks where Cisco 600 routers are deployed, as these devices often serve as primary connectivity points for multiple network segments.
The exploitation of CVE-2001-0058 aligns with tactics described in the ATT&CK framework under the T1499 category for Network Denial of Service, where adversaries target network infrastructure to disrupt services. This vulnerability also maps to the T1566 technique for Initial Access through malicious web content, as attackers can potentially use this flaw as part of a broader attack chain to gain persistent access to network resources. Organizations should consider implementing network segmentation strategies to limit the impact of such vulnerabilities and ensure that administrative access to network devices is restricted to trusted networks. The vulnerability also highlights the importance of regular security updates and patch management processes, as Cisco had released fixes for this issue in subsequent CBOS versions.
Mitigation strategies for this vulnerability should include immediate deployment of available security patches from Cisco, which would address the input validation flaw in the web server component. Network administrators should also consider disabling the web interface entirely if it is not essential for operations, as this removes the attack surface for this specific vulnerability. Additional defensive measures include implementing network access controls to restrict access to router management interfaces, configuring intrusion detection systems to monitor for suspicious URL patterns, and establishing robust monitoring procedures to detect potential exploitation attempts. Organizations should also conduct vulnerability assessments to identify other potentially affected devices within their network infrastructure and ensure that all network equipment is running supported firmware versions. The remediation process should include thorough testing of patches in controlled environments before deployment to production systems to prevent unintended service disruptions.