CVE-2019-19533
Description
An information leak flaw was found in the Linux kernel's USB digital video device driver. An attacker with a malicious USB device presenting itself as a 'Technotrend/Hauppauge USB DEC' device is able to issue commands to this specific device and leak kernel internal memory information. The highest threat from this vulnerability is a breach of data confidentiality.
Mitigation
As the ttusb_dec module will be auto-loaded when required, its use can be disabled by preventing the module from loading with the following instructions:
# echo "install ttusb_dec /bin/true" >> /etc/modprobe.d/disable-cifs.conf
The system will need to be restarted if the ttusb_dec module is already loaded. In most circumstances, the CIFS kernel module will be unable to be unloaded while the device 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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert: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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 2.4 | 2.4 | N/A |
| Attack Vector | Physical | Physical | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | Low | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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