CVE Vulnerabilities

CVE-2019-17185

Improper Synchronization

Published: Mar 21, 2020 | Modified: Apr 22, 2022
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
7.5 MODERATE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Ubuntu
LOW

In FreeRADIUS 3.0.x before 3.0.20, the EAP-pwd module used a global OpenSSL BN_CTX instance to handle all handshakes. This mean multiple threads use the same BN_CTX instance concurrently, resulting in crashes when concurrent EAP-pwd handshakes are initiated. This can be abused by an adversary as a Denial-of-Service (DoS) attack.

Weakness

The product utilizes multiple threads or processes to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes.

Affected Software

Name Vendor Start Version End Version
Freeradius Freeradius 3.0.0 (including) 3.0.20 (excluding)
Red Hat Enterprise Linux 7 RedHat freeradius-0:3.0.13-15.el7 *
Red Hat Enterprise Linux 8 RedHat freeradius:3.0-8030020200806223029.1e4bbb35 *
Freeradius Ubuntu bionic *
Freeradius Ubuntu eoan *
Freeradius Ubuntu esm-infra/bionic *
Freeradius Ubuntu trusty *
Freeradius Ubuntu upstream *
Freeradius Ubuntu xenial *

Extended Description

Synchronization refers to a variety of behaviors and mechanisms that allow two or more independently-operating processes or threads to ensure that they operate on shared resources in predictable ways that do not interfere with each other. Some shared resource operations cannot be executed atomically; that is, multiple steps must be guaranteed to execute sequentially, without any interference by other processes. Synchronization mechanisms vary widely, but they may include locking, mutexes, and semaphores. When a multi-step operation on a shared resource cannot be guaranteed to execute independent of interference, then the resulting behavior can be unpredictable. Improper synchronization could lead to data or memory corruption, denial of service, etc.

Potential Mitigations

References