Security Bulletin - Endpoint Security for Linux Threat Prevention update fixes privilege escalation vulnerability allowing unprivileged users to delete arbitrary files (CVE-2018-6693)
Security Bulletins ID:
SB10248
Last Modified: 2022-05-04 15:24:29 Etc/GMT
Last Modified: 2022-05-04 15:24:29 Etc/GMT
Summary
First Published: September 11, 2018
Article contents:
An unprivileged user can delete arbitrary files on a Linux system running ENSLTP 10.5.1, 10.5.0, and 10.2.3 Hotfix 1246778 and earlier. By exploiting a time of check to time of use (TOCTOU) race condition during a specific scanning sequence, the unprivileged user is able to perform a privilege escalation to delete arbitrary files.
CVE-2018-6693
By exploiting a time of check to time of use (TOCTOU) race condition during a specific scanning sequence, the unprivileged user is able to perform a privilege escalation to delete arbitrary files.
NOTE: The following links were not yet populated with CVE details at the time of publication of this Security Bulletin.
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-6693
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-6693
Remediation
To remediate this issue, go to the Product Downloads site, and download the applicable product hotfix files:
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.
Workaround
We highly recommend that all customers upgrade to the following ENSLTP versions:
Follow the instructions below to change the scan action from "delete" to "deny":
Acknowledgments
We credit RACK911Labs.com for reporting this flaw.
Frequently Asked Questions (FAQs)
How do I know if my product is vulnerable?
For ENSLTP:
Use the following instructions for ENSLTP:
What is CVSS?
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-2018-6693: Unprivileged user able to delete arbitrary files on the system
NOTE: The below CVSS version 3.0 vector was used to generate this score.
https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:L/E:P/RL:O/RC:C
Where can I find a list of all Security Bulletins?
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: | Race Condition Enabling Link Following (CWE-363) Privilege Escalation (CWE-274) |
CVE ID: | CVE-2018-6693 |
Severity Rating: | Medium |
CVSS v3 Base/Temporal Scores: | 5.6 / 5.1 |
Recommendations: | Upgrade to the following Endpoint Security for Linux Threat Prevention (ENSLTP) versions:
|
Security Bulletin Replacement: | None |
Affected Software: |
|
Location of updated software: | Product Downloads site |
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Article contents:
- Vulnerability Description
- Remediation
- Workaround
- Acknowledgments
- Frequently Asked Questions (FAQs)
- Resources
- Disclaimer
An unprivileged user can delete arbitrary files on a Linux system running ENSLTP 10.5.1, 10.5.0, and 10.2.3 Hotfix 1246778 and earlier. By exploiting a time of check to time of use (TOCTOU) race condition during a specific scanning sequence, the unprivileged user is able to perform a privilege escalation to delete arbitrary files.
CVE-2018-6693
By exploiting a time of check to time of use (TOCTOU) race condition during a specific scanning sequence, the unprivileged user is able to perform a privilege escalation to delete arbitrary files.
NOTE: The following links were not yet populated with CVE details at the time of publication of this Security Bulletin.
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-6693
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-6693
Remediation
To remediate this issue, go to the Product Downloads site, and download the applicable product hotfix files:
Product | Version | Type | File Name | Release Date |
ENSLTP | 10.2.3 Hotfix 1251530 | Hotfix | ISecTP-10.2.3-<build_number>-HF1251530-standalone.tar.gz ISecTP-10.2.3-<build_number>-HF1251530-ePO.zip |
September 11, 2018 |
ENSLTP | 10.5.1 Hotfix 1251617 | Hotfix | ISecTP-10.5.1-<build_number>-HF1251617-standalone.tar.gz ISecTP-10.5.1-<build_number>-HF1251617-ePO.zip |
September 11, 2018 |
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.
Workaround
We highly recommend that all customers upgrade to the following ENSLTP versions:
- ENSLTP 10.2.3 Hotfix 1251530
- ENSLTP 10.5.1 Hotfix 1251617
Follow the instructions below to change the scan action from "delete" to "deny":
- For standalone systems:
On-access scan:
Using isecav, change the primary or secondary scan action to "deny" instead of "delete" for both Threat Detection and Unwanted Programs. Ensure that you change this action for all the scan profiles – standard, highrisk, and lowrisk.
For detailed instructions on changing the policy, see the Product Guide or isecav main page.
On-demand scan:
Create the on-demand scan task with the primary or secondary scan action set to "Continue scanning" instead of "delete" for both Threat Detection and Unwanted Programs, for Full scan, Quick scan, and Custom scan tasks.
For detailed instructions on creating tasks, see the Product Guide.
Using isecav, change the primary or secondary scan action to "deny" instead of "delete" for both Threat Detection and Unwanted Programs. Ensure that you change this action for all the scan profiles – standard, highrisk, and lowrisk.
For detailed instructions on changing the policy, see the Product Guide or isecav main page.
On-demand scan:
Create the on-demand scan task with the primary or secondary scan action set to "Continue scanning" instead of "delete" for both Threat Detection and Unwanted Programs, for Full scan, Quick scan, and Custom scan tasks.
For detailed instructions on creating tasks, see the Product Guide.
- For managed systems:
On-access scan:
From ePolicy Orchestrator (ePO), create or modify an on-access scan policy for ENSLTP with the primary or secondary scan action set to "deny" instead of "delete" for both Threat Detection and Unwanted Programs.
For detailed instructions on changing the policy, see the Product Guide.
On-demand scan:
From ePO, set the primary or secondary scan action to "Continue scanning" instead of "delete" for both Threat Detection and Unwanted Programs, for Full scan, Quick scan, and custom scan tasks.
For detailed instructions on changing the policy, see the Product Guide.
NOTE: By setting the action to "Continue scanning", no action is taken on the file and it remains on the disk. So, consecutive on-demand scans for the same file generate repetitive detection and events.
From ePolicy Orchestrator (ePO), create or modify an on-access scan policy for ENSLTP with the primary or secondary scan action set to "deny" instead of "delete" for both Threat Detection and Unwanted Programs.
For detailed instructions on changing the policy, see the Product Guide.
On-demand scan:
From ePO, set the primary or secondary scan action to "Continue scanning" instead of "delete" for both Threat Detection and Unwanted Programs, for Full scan, Quick scan, and custom scan tasks.
For detailed instructions on changing the policy, see the Product Guide.
NOTE: By setting the action to "Continue scanning", no action is taken on the file and it remains on the disk. So, consecutive on-demand scans for the same file generate repetitive detection and events.
For product documents, go to the Product Documentation portal.
We credit RACK911Labs.com for reporting this flaw.
Frequently Asked Questions (FAQs)
How do I know if my product is vulnerable?
For ENSLTP:
Use the following instructions for ENSLTP:
- Log on to the system as root or equivalent user.
- Run the following command:
# /opt/isec/ens/threatprevention/bin/isecav --version
The product version is displayed.
What is CVSS?
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-2018-6693: Unprivileged user able to delete arbitrary files on the system
Base Score | 5.6 |
Attack Vector (AV) | Local (L) |
Attack Complexity (AC) | Low (L) |
Privileges Required (PR) | Low (L) |
User Interaction (UI) | Required (R) |
Scope (S) | Unchanged (U) |
Confidentiality (C) | None (N) |
Integrity (I) | High (H) |
Availability (A) | Low (L) |
Temporal Score (Overall) | 5.1 |
Exploitability (E) | Proof-of-Concept (P) |
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://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:L/E:P/RL:O/RC:C
Where can I find a list of all Security Bulletins?
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.