CVE Vulnerabilities

CVE-2019-18390

Out-of-bounds Read

Published: Dec 23, 2019 | Modified: Nov 16, 2020
CVSS 3.x
7.1
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
CVSS 2.x
3.6 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:P
RedHat/V2
RedHat/V3
3.3 LOW
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Ubuntu

An out-of-bounds read in the vrend_blit_need_swizzle function in vrend_renderer.c in virglrenderer through 0.8.0 allows guest OS users to cause a denial of service via VIRGL_CCMD_BLIT commands.

Weakness

The software reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Name Vendor Start Version End Version
Virglrenderer Virglrenderer_project * 0.8.0
Virglrenderer Ubuntu bionic *
Virglrenderer Ubuntu disco *
Virglrenderer Ubuntu eoan *
Virglrenderer Ubuntu trusty *
Virglrenderer Ubuntu upstream *

Potential Mitigations

  • Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
  • When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
  • Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
  • To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

References