CVE Vulnerabilities

CVE-2019-20200

Out-of-bounds Read

Published: Dec 31, 2019 | Modified: Jan 06, 2020
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

An issue was discovered in ezXML 0.8.3 through 0.8.6. The function ezxml_decode, while parsing crafted a XML file, performs incorrect memory handling, leading to a heap-based buffer over-read in the normalize line endings feature.

Weakness

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

Affected Software

Name Vendor Start Version End Version
Ezxml Ezxml_project 0.8.3 (including) 0.8.6 (including)
Mapcache Ubuntu bionic *
Mapcache Ubuntu groovy *
Mapcache Ubuntu hirsute *
Mapcache Ubuntu impish *
Mapcache Ubuntu kinetic *
Mapcache Ubuntu lunar *
Mapcache Ubuntu mantic *
Mapcache Ubuntu trusty *
Mapcache Ubuntu xenial *
Navit Ubuntu bionic *
Navit Ubuntu groovy *
Navit Ubuntu hirsute *
Navit Ubuntu impish *
Navit Ubuntu kinetic *
Navit Ubuntu lunar *
Navit Ubuntu mantic *
Navit Ubuntu trusty *
Navit Ubuntu xenial *
Netcdf Ubuntu bionic *
Netcdf Ubuntu groovy *
Netcdf Ubuntu hirsute *
Netcdf Ubuntu impish *
Netcdf Ubuntu kinetic *
Netcdf Ubuntu lunar *
Netcdf Ubuntu mantic *
Netcdf Ubuntu trusty *
Netcdf Ubuntu trusty/esm *
Netcdf Ubuntu xenial *
Netcdf-parallel Ubuntu groovy *
Netcdf-parallel Ubuntu hirsute *
Netcdf-parallel Ubuntu impish *
Netcdf-parallel Ubuntu kinetic *
Netcdf-parallel Ubuntu lunar *
Netcdf-parallel Ubuntu mantic *
Netcdf-parallel Ubuntu trusty *
Netcdf-parallel Ubuntu xenial *
Scilab Ubuntu bionic *
Scilab Ubuntu groovy *
Scilab Ubuntu hirsute *
Scilab Ubuntu impish *
Scilab Ubuntu kinetic *
Scilab Ubuntu lunar *
Scilab Ubuntu mantic *
Scilab Ubuntu trusty *
Scilab 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.

References