The privilege escalation vulnerability (CVE-2019-0211) affecting the Apache HTTP server could be exploited by users with the right to write and run scripts to gain root on Unix systems
An important privilege escalation vulnerability (CVE-2019-0211) affecting the Apache HTTP server could be exploited by users with the right to write and run scripts to gain root on Unix systems via scoreboard manipulation.
The flaw was discovered by Charles Fol and impacts all Apache HTTP Server releases from 2.4.17 to 2.4.38. The issue has been addressed with the release of Apache httpd 2.4.39
“In Apache HTTP Server 2.4 releases 2.4.17 to 2.4.38, with MPM event, worker or prefork, code executing in less-privileged child processes or threads (including scripts executed by an in-process scripting interpreter) could execute arbitrary code with the privileges of the parent process (usually root) by manipulating the scoreboard. Non-Unix systems are not affected.” reads the changelog.
The CVE-2019-0211 vulnerability poses severe risks when the web server is used for running shared hosting instances, in this scenario, users with limited permissions could exploit the flaw to get root privileges using scripts and run commands on vulnerable Apache web servers.
The expert pointed out that it is very common to give unprivileged users the ability to write their own scripts.
Apache also addressed two other important severity control bypass security vulnerabilities, one of them tracked as CVE-2019-0217.
“In Apache HTTP Server 2.4 release 2.4.38 and prior, a race condition in mod_auth_digest when running in a threaded server could allow a user with valid credentials to authenticate using another username, bypassing configured access control restrictions.” continues the changelog.
The second one, tracked as CVE-2019-0215, affects Apache 2.4.37 and 2.4.38.
“In Apache HTTP Server 2.4 releases 2.4.37 and 2.4.38, a bug in mod_ssl when using per-location client certificate verification with TLSv1.3 allowed a client supporting Post-Handshake Authentication to bypass configured access control restrictions.” reads the changelog.
The complete list of flaws addressed in Apache httpd his available here.
Pierluigi Paganini is member of the ENISA (European Union Agency for Network and Information Security) Threat Landscape Stakeholder Group and Cyber G7 Group, he is also a Security Evangelist, Security Analyst and Freelance Writer.
Editor-in-Chief at "Cyber Defense Magazine", Pierluigi is a cyber security expert with over 20 years experience in the field, he is Certified Ethical Hacker at EC Council in London. The passion for writing and a strong belief that security is founded on sharing and awareness led Pierluigi to find the security blog "Security Affairs" recently named a Top National Security Resource for US.
Pierluigi is a member of the "The Hacker News" team and he is a writer for some major publications in the field such as Cyber War Zone, ICTTF, Infosec Island, Infosec Institute, The Hacker News Magazine and for many other Security magazines.
Author of the Books "The Deep Dark Web" and “Digital Virtual Currency and Bitcoin”.