CVE-2019-0211:Proof of Concept for Apache Root Privilege Escalation Vulnerability Published
Researcher publishes proof of concept (PoC) for local root privilege escalation bug patched by Apache last week.
Antecedentes
Last week, Apache published a security update to address six vulnerabilities in HTTP Server versions 2.4.17 to 2.4.38. This release includes a fix for CVE-2019-0211, a local root privilege escalation vulnerability that could lead to arbitrary code execution.
Análisis
The vulnerability, dubbed CARPE (DIEM), exists in Apache Multi-Processing Modules (MPMs) such as mod_prefork, mod_worker and mod_event. Charles Fol, the researcher who discovered and named the vulnerability, targeted mod_prefork for his breakdown and subsequent PoC.
According to Fol, Apache uses a shared-memory area known as scoreboard to keep tabs on worker processes (lower privileges) managed by mod_prefork (root privileges). Exploitation of this vulnerability requires an attacker to gain read/write access to a worker process (through a separate exploit) in order to manipulate the scoreboard to point to a rogue worker before an Apache graceful restart is initiated by logrotate.
In their advisory, Apache noted that non-Unix systems are unaffected by CVE-2019-0211. This is likely due to the fact that the vulnerability is triggered by an Apache graceful restart (apache2ctl graceful), which is normally executed by logrotate every morning on *Nix systems.
Proof of Concept
Fol published his PoC to Github on April 8. In his blog, he notes this exploit is “between a POC and a proper exploit.” The expectation is now that the PoC is publicly available, it will most likely be refined further and ultimately leveraged by attackers in the wild. This is of great concern on shared hosting environments, where a malicious user could leverage this exploit to gain root access on the host and access files shared by other users on the host environment.
Solución
CVE-2019-0211 is patched in Apache HTTP Server version 2.4.39. *Nix distributions including Ubuntu, Debian, and SuSE have package updates available for install. FreeBSD posted an advisory, but there is no security update available for it yet. Users are encouraged to install these updates as soon as possible.
Additionally, cPanel released a security update for EasyApache 4 that addresses this vulnerability.
Identificación de los sistemas afectados
A list of Nessus plugins to identify these vulnerabilities will appear here as they’re released.
Nessus users scanning for vulnerable versions of Apache HTTP Server will see the following scan output.
Continuous monitoring via Nessus Network Monitor will result in the following output:
Obtenga más información
- Apache Security Advisory
- Charles Fol's description of CARPE (DIEM)
- Ubuntu Security Advisory
- Debian Security Tracker for CVE-2019-0211
- SuSE: CVE-2019-0211
- FreeBSD: Apache -- Multiple vulnerabilities
- EasyApache 4 Apr 3 Release
Únase al Equipo de respuesta de seguridad de Tenable en Tenable Community.
Obtenga más información sobre Tenable, la primera plataforma de Cyber Exposure para el control integral de la superficie de ataque moderna.
Get a free 60-day trial of Tenable.io Vulnerability Management.
Artículos relacionados
Microsoft’s May 2024 Patch Tuesday Addresses 59 CVEs (CVE-2024-30051, CVE-2024-30040)
May 14, 2024Microsoft addresses 59 CVEs in its May 2024 Patch Tuesday release with one critical vulnerability and three zero-day vulnerabilities, two of which were exploited in the wild.
CVE-2024-21793, CVE-2024-26026: Proof of Concept Available for F5 BIG-IP Next Central Manager Vulnerabilities
May 9, 2024Researchers disclose multiple vulnerabilities in F5 BIG-IP Next Central Manager and provide proof-of-concept exploit code, which could lead to exposure of hashed passwords.
Cybersecurity Snapshot: Attackers Pounce on Unpatched Vulns, DBIR Says, as Critical Infrastructure Orgs Benefit from CISA’s Alert Program
May 3, 2024Verizon’s DBIR found that hackers are having a field day exploiting vulnerabilities to gain initial access. Plus, a CISA program is helping critical infrastructure organizations prevent ransomware attacks. In addition, check out what Tenable’s got planned for RSA Conference 2024. And get the latest on the Change Healthcare breach. And much more!
Microsoft’s May 2024 Patch Tuesday Addresses 59 CVEs (CVE-2024-30051, CVE-2024-30040)
May 14, 2024Microsoft addresses 59 CVEs in its May 2024 Patch Tuesday release with one critical vulnerability and three zero-day vulnerabilities, two of which were exploited in the wild.
Tenable Cloud Security Study Reveals a Whopping 95% of Surveyed Organizations Suffered a Cloud-Related Breach Over an 18-Month Period
May 14, 2024The finding from the Tenable 2024 Cloud Security Outlook study is a clear sign of the need for proactive and robust cloud security. Read on to learn more about the study’s findings, including the main challenges cloud security teams face, their strategies for better protecting their cloud infrastructure and the tools they use to measure success.
Shifting the Paradigm: Why the Cyber Insurance Industry Should Focus on Preventive Security
May 13, 2024As claims and losses climb, it’s clear that preventive security should be prioritized more when designing a cyber insurance policy. Here’s why preventive security investments are cost effective and can lead to lower premiums.
- Vulnerability Management