Security Advisory

Published: August 8, 2017
Last Update: October 17, 2019

A vulnerability scan of the ACOS management interface indicated the presence of responses to ICMP timestamp requests. The information in these responses could be leveraged in other exploits of the ACOS system. Accordingly, the following vulnerabilities are addressed in this document.

Item Score
# Vulnerability ID Source Score Summary
1 generic-icmp-timestamp Rapid7 1 Moderate ICMP timestamp response [1]
2 CVE-1999-0524 CVSS 2.0 0.0 Low ICMP timestamp response [2]
Affected Releases

The table below indicates releases of ACOS exposed to these vulnerabilities and ACOS releases that address these issues or are otherwise unaffected by them.

Customers using affected ACOS releases can overcome vulnerability exposures by updating to the indicated resolved release. If the table does not list a corresponding resolved or unaffected release, then no ACOS release update is currently available.

Releases Affected Releases Resolved or Unaffected



4.1.1 – 4.1.1-P2


4.1.100 – 4.1.100-P5-SP1


4.1.0 – 4.1.0-P8


3.1.0-P1 – 3.2.1-P1


2.8.2 – 2.8.2-P8


2.7.2 – 2.7.2-P7

4.1.0-P9, 4.1.1-P3

2.7.1 – 2.7.1-GR1-P1

4.1.0-P9, 4.1.1-P3

2.6.1-GR1 – 2.6.1-GR1-P16

4.1.0-P9, 4.1.1-P3

Workarounds and Mitigations

Common security best practices in the industry for network appliance management and control planes can enhance protection against remote malicious attacks. Limit the exploitable attack surface for critical, infrastructure, networking equipment through the use of access lists or firewall filters to and from only trusted, administrative networks or hosts.

Software Updates

Software updates that address these vulnerabilities are or will be published at the following URL:

Vulnerability Details

The following table shares brief descriptions for the vulnerabilities addressed in this document.

Vulnerability ID Vulnerability Description

The remote host responded to an ICMP timestamp request. The ICMP timestamp response contains the remote host's date and time. This information could theoretically be used against some systems to exploit weak time-based random number generators in other services.

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In addition, the versions of some operating systems can be accurately fingerprinted by analyzing their responses to invalid ICMP timestamp requests.


ICMP information such as (1) netmask and (2) timestamp is allowed from arbitrary hosts.

Related Links
Ref # General Link
[1] Rapid7: ICMP timestamp response
[2] NIST NVD, CVE-1999-0524
Modification History
Revision Date Description
1.0 August 8, 2018

Initial Publication

2.0 October 17, 2019

Added 4.1.100 release family.

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