CVE-2019-19523
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Description
A flaw was found in the Linux kernel’s implementation for ADU devices from Ontrak Control Systems, where an attacker with administrative privileges and access to a local account could pre-groom the memory and physically disconnect or unload a module. The attacker must be able to access either of these two events to trigger the use-after-free, and then race the access to the use-after-free, to create a situation where key USB structs can be manipulated into corrupting memory.
Mitigation
As the system module will be auto-loaded when a device that uses the driver is attached (via USB), its use can be disabled by preventing the module from loading with the following instructions:
# echo "install adutux /bin/true" >> /etc/modprobe.d/disable-adutux.conf
The system will need to be restarted if the adutux module are loaded. In most circumstances, the kernel modules will be unable to be unloaded while any hardware is in use.
If the system requires this module to work correctly, this mitigation may not be suitable.
If you need further assistance, see KCS article https://access.redhat.com/solutions/41278 or contact Red Hat Global Support Services.
Additional information
- Bugzilla 1783434: kernel: use-after-free caused by a malicious USB device in the drivers/usb/misc/adutux.c driver
- CWE-416->CWE-476: Use After Free leads to NULL Pointer Dereference
- FAQ: Frequently asked questions about CVE-2019-19523
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
Red Hat | NVD | |
---|---|---|
CVSS v3 Base Score | 7.8 | 4.6 |
Attack Vector | Local | Physical |
Attack Complexity | Low | Low |
Privileges Required | Low | None |
User Interaction | None | None |
Scope | Unchanged | Unchanged |
Confidentiality Impact | High | None |
Integrity Impact | High | None |
Availability Impact | High | High |
CVSS v3 Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
For more information, see https://access.redhat.com/solutions/762393.
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
- "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
- "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.
What can I do if my product is listed as "Will not fix"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
- Apply a mitigation (if one exists).
- Open a support case to request a prioritization of releasing a fix for this vulnerability.
What can I do if my product is listed as "Fix deferred"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Apply a mitigation (if one exists).
- Open a support case to request a prioritization of releasing a fix for this vulnerability.
- Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
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