ID CVE-2019-1732
Summary A vulnerability in the Remote Package Manager (RPM) subsystem of Cisco NX-OS Software could allow an authenticated, local attacker with administrator credentials to leverage a time-of-check, time-of-use (TOCTOU) race condition to corrupt local variables, which could lead to arbitrary command injection. The vulnerability is due to the lack of a proper locking mechanism on critical variables that need to stay static until used. An attacker could exploit this vulnerability by authenticating to an affected device and issuing a set of RPM-related CLI commands. A successful exploit could allow the attacker to perform arbitrary command injection. The attacker would need administrator credentials for the targeted device.
References
Vulnerable Configurations
  • cpe:2.3:h:cisco:nexus_3000
    cpe:2.3:h:cisco:nexus_3000
  • cpe:2.3:h:cisco:nexus_3100
    cpe:2.3:h:cisco:nexus_3100
  • cpe:2.3:h:cisco:nexus_3100-z
    cpe:2.3:h:cisco:nexus_3100-z
  • cpe:2.3:h:cisco:nexus_3100v
    cpe:2.3:h:cisco:nexus_3100v
  • cpe:2.3:h:cisco:nexus_3200
    cpe:2.3:h:cisco:nexus_3200
  • cpe:2.3:h:cisco:nexus_3400
    cpe:2.3:h:cisco:nexus_3400
  • cpe:2.3:h:cisco:nexus_3500
    cpe:2.3:h:cisco:nexus_3500
  • cpe:2.3:h:cisco:nexus_3524-x
    cpe:2.3:h:cisco:nexus_3524-x
  • cpe:2.3:h:cisco:nexus_3524-xl
    cpe:2.3:h:cisco:nexus_3524-xl
  • cpe:2.3:h:cisco:nexus_3548-x
    cpe:2.3:h:cisco:nexus_3548-x
  • cpe:2.3:h:cisco:nexus_3548-xl
    cpe:2.3:h:cisco:nexus_3548-xl
  • cpe:2.3:h:cisco:nexus_9000
    cpe:2.3:h:cisco:nexus_9000
  • cpe:2.3:h:cisco:nexus_9200
    cpe:2.3:h:cisco:nexus_9200
  • cpe:2.3:h:cisco:nexus_9300
    cpe:2.3:h:cisco:nexus_9300
  • Cisco Nexus 9500
    cpe:2.3:h:cisco:nexus_9500
  • cpe:2.3:h:cisco:nexus_3600
    cpe:2.3:h:cisco:nexus_3600
CVSS
Base: 6.9
Impact:
Exploitability:
CWE CWE-78
CAPEC
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.
  • Command Delimiters
    An attack of this type exploits a programs' vulnerabilities that allows an attacker's commands to be concatenated onto a legitimate command with the intent of targeting other resources such as the file system or database. The system that uses a filter or a blacklist input validation, as opposed to whitelist validation is vulnerable to an attacker who predicts delimiters (or combinations of delimiters) not present in the filter or blacklist. As with other injection attacks, the attacker uses the command delimiter payload as an entry point to tunnel through the application and activate additional attacks through SQL queries, shell commands, network scanning, and so on.
  • Exploiting Multiple Input Interpretation Layers
    An attacker supplies the target software with input data that contains sequences of special characters designed to bypass input validation logic. This exploit relies on the target making multiples passes over the input data and processing a "layer" of special characters with each pass. In this manner, the attacker can disguise input that would otherwise be rejected as invalid by concealing it with layers of special/escape characters that are stripped off by subsequent processing steps. The goal is to first discover cases where the input validation layer executes before one or more parsing layers. That is, user input may go through the following logic in an application: In such cases, the attacker will need to provide input that will pass through the input validator, but after passing through parser2, will be converted into something that the input validator was supposed to stop.
  • Argument Injection
    An attacker changes the behavior or state of a targeted application through injecting data or command syntax through the targets use of non-validated and non-filtered arguments of exposed services or methods.
  • OS Command Injection
    In this type of an attack, an adversary injects operating system commands into existing application functions. An application that uses untrusted input to build command strings is vulnerable. An adversary can leverage OS command injection in an application to elevate privileges, execute arbitrary commands and compromise the underlying operating system.
refmap via4
bid 108361
cisco 20190515 Cisco NX-OS Software Remote Package Manager Command Injection Vulnerability
Last major update 15-05-2019 - 13:29
Published 15-05-2019 - 13:29
Last modified 17-05-2019 - 09:24
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