SB2019062808 - XXE in expat library
Published: June 28, 2019 Updated: June 20, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) XML External Entity injection (CVE-ID: CVE-2018-20843)
The vulnerability allows a remote attacker to gain access to sensitive information.
The vulnerability exists due to insufficient validation of user-supplied XML input including XML names that contain a large number of colons. A remote attacker can pass a specially crafted XML code to the affected application and view contents of arbitrary files on the system or initiate requests to external systems.
Successful exploitation of the vulnerability may allow an attacker to view contents of arbitrary file on the server or perform network scanning of internal and external infrastructure.
Remediation
Install update from vendor's website.
References
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=5226
- https://github.com/libexpat/libexpat/blob/R_2_2_7/expat/Changes
- https://github.com/libexpat/libexpat/issues/186
- https://github.com/libexpat/libexpat/pull/262
- https://github.com/libexpat/libexpat/pull/262/commits/11f8838bf99ea0a6f0b76f9760c43704d00c4ff6
- https://usn.ubuntu.com/4040-1/
- https://usn.ubuntu.com/4040-2/