CVE Vulnerabilities


Out-of-bounds Read

Published: Aug 12, 2020 | Modified: Sep 30, 2020
CVSS 3.x
CVSS 2.x

An issue was discovered in Qt through 5.12.9, and 5.13.x through 5.15.x before 5.15.1. read_xbm_body in gui/image/qxbmhandler.cpp has a buffer over-read.


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

Affected Software

Name Vendor Start Version End Version
Qt Qt * 5.12.9
Qt Qt 5.13.0 *
Red Hat Enterprise Linux 7 RedHat qt-1:4.8.7-9.el7_9 *
Red Hat Enterprise Linux 7 RedHat qt5-qtbase-0:5.9.7-5.el7_9 *
Red Hat Enterprise Linux 8 RedHat qt5-qtbase-0:5.12.5-8.el8 *
Qt4-x11 Ubuntu bionic *
Qt4-x11 Ubuntu esm-infra/xenial *
Qt4-x11 Ubuntu trusty *
Qt4-x11 Ubuntu trusty/esm *
Qt4-x11 Ubuntu xenial *
Qtbase-opensource-src Ubuntu bionic *
Qtbase-opensource-src Ubuntu esm-infra/xenial *
Qtbase-opensource-src Ubuntu focal *
Qtbase-opensource-src Ubuntu trusty *
Qtbase-opensource-src Ubuntu xenial *

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.