Security Bulletin - Threat Intelligence Exchange Server update fixes a DHCP client vulnerability (CVE-2018-5732) and an issue with SSH host keys generation (CVE-2018-6695)
Security Bulletins ID:
SB10253
Last Modified: 5/4/2022
Last Modified: 5/4/2022
Summary
First Published: September 28, 2018
Article contents:
CVE-2018-5732
An out-of-bound memory access flaw was found in the way dhclient processed a DHCP response packet. A malicious DHCP server could potentially use this flaw to crash dhclient processes running on DHCP client machines, via a crafted DHCP response packet.
https://access.redhat.com/security/cve/cve-2018-5732
CVE-2018-6695
SSH host keys generation vulnerability in the server in Threat Intelligence Exchange Server (TIE Server) 1.3.0, 2.0.x, 2.1.x, 2.2.0, 2.3.x allows man-in-the-middle attackers to spoof servers via acquiring keys from another environment.
NOTE: The following links were not yet populated with CVE details at the time of publication of this Security Bulletin.
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-6695
https://nvd.nist.gov/vuln/detail/CVE-2018-6695
Remediation
TIE Server 2.3.0 was released in September 2018 to remediate these issues. The TIE Server 2.3.0 release did not fully address CVE-2018-6695 when used to do a new installation on VMware. When TIE Server 2.3.0 was installed as an update, the issues were correctly remediated. To remediate these issues, install or update to TIE Server 2.3.1 HF2.
Go to the Product Downloads site and download the applicable product hotfix file:
Download and Installation Instructions
For instructions to download product updates and hotfixes, see KB56057 - How to download Enterprise product updates and documentation. Review the Release Notes and the Installation Guide for instructions on how to install these updates. All documentation is available on the Product Documentation site.
Product Specific Notes
CVE-2018-6695
Upgrading to TIE Server 2.3.1 HF2 automatically generates new SSH host keys for the appliance. Due to this procedure, the first subsequent SSH connection to the server receives a warning message stating that Remote host identification has changed. This behavior is expected and can be solved by validating the new key.
Workaround
CVE-2018-5732
None. Install the available version update.
CVE-2018-6695
Regenerate the existing SSH host keys to ensure their uniqueness. To generate new keys manually, run the following commands:
shred -ufz /etc/ssh/ssh_host_*
service sshd restart
NOTE: For TIE Server 2.1.1 or earlier, RSA host keys must be enabled before generating new keys. To do that, configure the following values in the /etc/ssh/sshd_config file:
Mitigations are provided with the security fixes packaged in the product release.
Acknowledgments
We credit Felix Wilhelm from Google Security Team for reporting CVE-2018-5732.
Frequently Asked Questions (FAQs)
How do I know if my product is vulnerable?
For Appliances:
Use the following instructions for Appliance-based products:
CVSS, or Common Vulnerability Scoring System, is the result of the National Infrastructure Advisory Council’s effort to standardize a system of assessing the criticality of a vulnerability. This system offers an unbiased criticality score between 0 and 10 that customers can use to judge how critical a vulnerability is and plan accordingly. For more information, visit the CVSS website at: http://www.first.org/cvss/.
When calculating CVSS scores, we've adopted a philosophy that fosters consistency and repeatability. Our guiding principle for CVSS scoring is to score the exploit under consideration by itself. We consider only the immediate and direct impact of the exploit under consideration. We do not factor into a score any potential follow-on exploits that might be made possible by the successful exploitation of the issue being scored.
What are the CVSS scoring metrics?
All Security Bulletins are published on our Knowledge Center. Security Bulletins are retired (removed) once a product is both End of Sale and End of Support (End of Life).
How do I report a product vulnerability to you?
If you have information about a security issue or vulnerability with a product, follow the instructions provided in KB95563 - Report a vulnerability.
How do you respond to this and any other reported security flaws?
Our key priority is the security of our customers. If a vulnerability is found within any of our software or services, we work closely with the relevant security software development team to ensure the rapid and effective development of a fix and communication plan.
We only publish Security Bulletins if they include something actionable such as a workaround, mitigation, version update, or hotfix. Otherwise, we would simply be informing the hacker community that our products are a target, putting our customers at greater risk. For products that are updated automatically, a non-actionable Security Bulletin might be published to acknowledge the discoverer.
To view our PSIRT policy, see KB95564 - About PSIRT.
Resources
Disclaimer
The information provided in this Security Bulletin is provided as is without warranty of any kind. We disclaim all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall we or our suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits, or special damages, even if we or our suppliers have been advised of the possibility of such damages. Some states don't allow the exclusion or limitation of liability for consequential or incidental damages, so the preceding limitation may not apply.
Any future product release dates mentioned in this Security Bulletin are intended to outline our general product direction, and they shouldn't be relied on in making a purchasing decision. The product release dates are for information purposes only, and may not be incorporated into any contract. The product release dates aren't a commitment, promise, or legal obligation to deliver any material, code, or functionality. The development, release, and timing of any features or functionality described for our products remain at our sole discretion and may be changed or canceled at any time.
| Impact of Vulnerability: | Buffer Overflow (CWE-726, OWASP 2004:A5) Use of Multiple Resources with Duplicate Identifier (CWE-694) |
| CVE ID: | CVE-2018-5732 CVE-2018-6695 |
| Severity Rating: | CVE-2018-5732: High CVE-2018-6695: Medium |
| CVSS v3 Base/Temporal Scores: | CVE-2018-5732: 7.5/6.5 CVE-2018-6695: 6.1/5.3 |
| Recommendations: | Install or update to Threat Intelligence Exchange (TIE) Server 2.3.1 Hotfix 2 (HF2) |
| Security Bulletin Replacement: | None |
| Affected Software: | TIE Server 1.3.0, TIE Server 2.0.x, TIE Server 2.1.x, TIE Server 2.2.0, TIE Server 2.3.x |
| Location of updated software: | Product Downloads site |
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Article contents:
- Vulnerability Description
- Remediation
- Product Specific Notes
- Workaround
- Mitigations
- Acknowledgments
- Frequently Asked Questions (FAQs)
- Resources
- Disclaimer
CVE-2018-5732
An out-of-bound memory access flaw was found in the way dhclient processed a DHCP response packet. A malicious DHCP server could potentially use this flaw to crash dhclient processes running on DHCP client machines, via a crafted DHCP response packet.
https://access.redhat.com/security/cve/cve-2018-5732
CVE-2018-6695
SSH host keys generation vulnerability in the server in Threat Intelligence Exchange Server (TIE Server) 1.3.0, 2.0.x, 2.1.x, 2.2.0, 2.3.x allows man-in-the-middle attackers to spoof servers via acquiring keys from another environment.
NOTE: The following links were not yet populated with CVE details at the time of publication of this Security Bulletin.
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-6695
https://nvd.nist.gov/vuln/detail/CVE-2018-6695
Remediation
TIE Server 2.3.0 was released in September 2018 to remediate these issues. The TIE Server 2.3.0 release did not fully address CVE-2018-6695 when used to do a new installation on VMware. When TIE Server 2.3.0 was installed as an update, the issues were correctly remediated. To remediate these issues, install or update to TIE Server 2.3.1 HF2.
Go to the Product Downloads site and download the applicable product hotfix file:
| Product | Version | Type | File Name | Release Date |
| TIE Server | 2.3.1 HF2 | Hotfix | TIE Server 2.3.1.138 | September 10, 2019 |
Download and Installation Instructions
For instructions to download product updates and hotfixes, see KB56057 - How to download Enterprise product updates and documentation. Review the Release Notes and the Installation Guide for instructions on how to install these updates. All documentation is available on the Product Documentation site.
Product Specific Notes
CVE-2018-6695
Upgrading to TIE Server 2.3.1 HF2 automatically generates new SSH host keys for the appliance. Due to this procedure, the first subsequent SSH connection to the server receives a warning message stating that Remote host identification has changed. This behavior is expected and can be solved by validating the new key.
Workaround
CVE-2018-5732
None. Install the available version update.
CVE-2018-6695
Regenerate the existing SSH host keys to ensure their uniqueness. To generate new keys manually, run the following commands:
shred -ufz /etc/ssh/ssh_host_*
service sshd restart
NOTE: For TIE Server 2.1.1 or earlier, RSA host keys must be enabled before generating new keys. To do that, configure the following values in the /etc/ssh/sshd_config file:
HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key
Mitigations#HostKey /etc/ssh/ssh_host_dsa_key
Mitigations are provided with the security fixes packaged in the product release.
Acknowledgments
We credit Felix Wilhelm from Google Security Team for reporting CVE-2018-5732.
Frequently Asked Questions (FAQs)
How do I know if my product is vulnerable?
For Appliances:
Use the following instructions for Appliance-based products:
- Open the Administrator's User Interface (UI).
- Click the About link. The product version displays.
CVSS, or Common Vulnerability Scoring System, is the result of the National Infrastructure Advisory Council’s effort to standardize a system of assessing the criticality of a vulnerability. This system offers an unbiased criticality score between 0 and 10 that customers can use to judge how critical a vulnerability is and plan accordingly. For more information, visit the CVSS website at: http://www.first.org/cvss/.
When calculating CVSS scores, we've adopted a philosophy that fosters consistency and repeatability. Our guiding principle for CVSS scoring is to score the exploit under consideration by itself. We consider only the immediate and direct impact of the exploit under consideration. We do not factor into a score any potential follow-on exploits that might be made possible by the successful exploitation of the issue being scored.
What are the CVSS scoring metrics?
- CVE-2018-5732: A specially constructed response from a malicious server can cause a buffer overflow in dhclient
Base Score 7.5 Attack Vector (AV) Adjacent Network (A) Attack Complexity (AC) High (H) Privileges Required (PR) None (N) User Interaction (UI) None (N) Scope (S) Unchanged (U) Confidentiality (C) High (H) Integrity (I) High (H) Availability (A) High (H) Temporal Score (Overall) 6.5 Exploitability (E) Unproven (U) Remediation Level (RL) Official Fix (O) Report Confidence (RC) Confirmed (C)
NOTE: The below CVSS version 3.0 vector was used to generate this score.
https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
- CVE-2018-6695: Duplicate SSH host keys: SSH host keys generation vulnerability in TIE Server allows man-in-the-middle attackers to spoof servers via acquiring keys from another environment
Base Score 6.1 Attack Vector (AV) Adjacent (A) Attack Complexity (AC) High (H) Privileges Required (PR) Low (L) User Interaction (UI) Required (R) Scope (S) Unchanged (U) Confidentiality (C) High (H) Integrity (I) High (H) Availability (A) None (N) Temporal Score (Overall) 5.3 Exploitability (E) Unproven (U) Remediation Level (RL) Official Fix (O) Report Confidence (RC) Confirmed (C)
NOTE: The below CVSS version 3.0 vector was used to generate this score.
https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:A/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C
All Security Bulletins are published on our Knowledge Center. Security Bulletins are retired (removed) once a product is both End of Sale and End of Support (End of Life).
How do I report a product vulnerability to you?
If you have information about a security issue or vulnerability with a product, follow the instructions provided in KB95563 - Report a vulnerability.
How do you respond to this and any other reported security flaws?
Our key priority is the security of our customers. If a vulnerability is found within any of our software or services, we work closely with the relevant security software development team to ensure the rapid and effective development of a fix and communication plan.
We only publish Security Bulletins if they include something actionable such as a workaround, mitigation, version update, or hotfix. Otherwise, we would simply be informing the hacker community that our products are a target, putting our customers at greater risk. For products that are updated automatically, a non-actionable Security Bulletin might be published to acknowledge the discoverer.
To view our PSIRT policy, see KB95564 - About PSIRT.
Resources
To contact Technical Support, go to the Create a Service Request page and log on to the ServicePortal.
- If you are a registered user, type your User ID and Password, and then click Log In.
- If you are not a registered user, click Register and complete the fields to have your password and instructions emailed to you.
Disclaimer
The information provided in this Security Bulletin is provided as is without warranty of any kind. We disclaim all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall we or our suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits, or special damages, even if we or our suppliers have been advised of the possibility of such damages. Some states don't allow the exclusion or limitation of liability for consequential or incidental damages, so the preceding limitation may not apply.
Any future product release dates mentioned in this Security Bulletin are intended to outline our general product direction, and they shouldn't be relied on in making a purchasing decision. The product release dates are for information purposes only, and may not be incorporated into any contract. The product release dates aren't a commitment, promise, or legal obligation to deliver any material, code, or functionality. The development, release, and timing of any features or functionality described for our products remain at our sole discretion and may be changed or canceled at any time.
