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Cisco Patches High-Severity Vulnerabilities in Data Center OS

Cisco’s semiannual FXOS and NX-OS security advisory bundle resolves two high- and two medium-severity vulnerabilities.

Technology giant Cisco on Wednesday released its semiannual FXOS and NX-OS security advisory bundle with information on four vulnerabilities, including two high-severity flaws in NX-OS software.

The first of the high-severity bugs, CVE-2024-20321, exists because External Border Gateway Protocol (eBGP) traffic “is mapped to a shared hardware rate-limiter queue”, allowing an unauthenticated, remote attacker to send large amounts of traffic and cause a denial-of-service (DoS) condition.

According to Cisco, under certain conditions, the security defect impacts Nexus 3600 series switches and Nexus 9500 R-series line cards, including the following product IDs: N3K-C36180YC-R, N3K-C3636C-R, N9K-X9624D-R2, N9K-X9636C-R, N9K-X9636C-RX, N9K-X9636Q-R, and N9K-X96136YC-R.

The second issue, tracked as CVE-2024-20267, exists because processing an ingress MPLS frame lacked proper error checking. An unauthenticated, remote attacker could encapsulate a crafted IPv6 packet in an MPLS frame and send it to a vulnerable device to cause a DoS condition.

The issue impacts Nexus 3000, Nexus 5500, Nexus 5600, Nexus 6000, Nexus 7000, and Nexus 9000 series switches that have MPLS configured.

NX-OS software versions 9.3(12), 10.2(6), and 10.3(4a) resolve these vulnerabilities.

On Wednesday, Cisco also announced patches for two medium-severity flaws impacting its FXOS and NX-OS software.

The first affects the handling of specific fields in a Link Layer Discovery Protocol (LLDP) frame and could allow an attacker to crash the LLDP service on the affected device.

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The second bug was found in the access control list (ACL) programming for port channel subinterfaces of Nexus 3000 and 9000 series switches in standalone NX-OS mode and could be exploited remotely, without authentication, to bypass ACL protections.

A fifth issue resolved on Wednesday impacts the UCS 6400 and 6500 series fabric interconnects in Intersight Managed Mode (IMM). Also a medium-severity vulnerability, it could be exploited by unauthenticated, remote attackers to cause a DoS condition.

Cisco says it is not aware of any of these security defects being exploited in attacks. Additional information can be found on Cisco’s security advisories page.

Related: CISA Urges Patching of Cisco ASA Flaw Exploited in Ransomware Attacks

Related: Cisco Patches Critical Vulnerabilities in Enterprise Communication Devices

Related: Cisco Patches Critical Vulnerability in Enterprise Collaboration Products

Written By

Ionut Arghire is an international correspondent for SecurityWeek.


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