Vulnerabilities > CVE-2019-1901 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Cisco Nx-Os
Attack vector
ADJACENT_NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
A vulnerability in the Link Layer Discovery Protocol (LLDP) subsystem of Cisco Nexus 9000 Series Application Centric Infrastructure (ACI) Mode Switch Software could allow an adjacent, unauthenticated attacker to cause a denial of service (DoS) condition or execute arbitrary code with root privileges. The vulnerability is due to improper input validation of certain type, length, value (TLV) fields of the LLDP frame header. An attacker could exploit this vulnerability by sending a crafted LLDP packet to the targeted device. A successful exploit may lead to a buffer overflow condition that could either cause a DoS condition or allow the attacker to execute arbitrary code with root privileges. Note: This vulnerability cannot be exploited by transit traffic through the device; the crafted packet must be targeted to a directly connected interface. This vulnerability affects Cisco Nexus 9000 Series Fabric Switches in ACI mode if they are running a Cisco Nexus 9000 Series ACI Mode Switch Software release prior to 13.2(7f) or any 14.x release.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Overflow Buffers Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
- Client-side Injection-induced Buffer Overflow This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
- Filter Failure through Buffer Overflow In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
- MIME Conversion An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.
Nessus
| NASL family | CISCO |
| NASL id | CISCO-SA-20190731-NXOS-BO.NASL |
| description | According to its self-reported version, the Cisco NX-OS Software in ACI mode is affected by a buffer overflow vulnerability. An unauthenticated, adjacent attacker could exploit this vulnerability, via a specially crafted Link Layer Discovery Protocol (LLDP) packet, to cause a denial-of-service condition or potentially execute arbitrary code with root privileges. Please see the reference Cisco BID and Cisco Security Advisory for more information. |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 128532 |
| published | 2019-09-06 |
| reporter | This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/128532 |
| title | Cisco Nexus 9000 Series Fabric Switches ACI Mode Link Layer Discovery Protocol Buffer Overflow Vulnerability |
| code | |