New Systemd Privilege Escalation Flaws Affect Most Linux Distributions

Jan 10, 2019

Security researchers have discovered three vulnerabilities in
Systemd, a popular init system and service manager for most Linux
operating systems, that could allow unprivileged local attackers or
malicious programs to gain root access on the targeted systems.

The vulnerabilities, assigned as CVE-2018-16864, CVE-2018-16865,
and CVE-2018-16866, actually resides in the “systemd-journald”
service that collects information from different sources and
creates event logs by logging information in the journal.

The vulnerabilities, which were discovered and reported by security
researchers at Qualys, affect all systemd-based Linux
distributions, including Redhat and Debian,
according to the researchers.

However, some Linux distros such as SUSE Linux Enterprise 15,
openSUSE Leap 15.0, and Fedora 28 and 29 are not affected, as
“their userspace [code] is compiled with GCC’s -fstack-clash-protection ^[3].”

The first two flaws are memory corruptions issues, while the
third one is an out-of-bounds read issue in systemd-journald that
can leak sensitive process memory data.

Researchers have successfully created proof-of-concept exploits,
which they are planning to release in the near future.

“We developed an exploit for CVE-2018-16865 and CVE-2018-16866
that obtains a local root shell in 10 minutes on i386 and 70
minutes on amd64, on average,” the researchers write in
an advisory published Wednesday.
^[4]

CVE-2018-16864 is similar to a Stack Clash vulnerability Qualys
researchers discovered in 2017 that can be exploited by malware or
low privileged users to escalate their permission to root.

According to the researchers, CVE-2018-16864 existed in
systemd’s codebase since April 2013 (systemd v203) and became
exploitable in February 2016 (systemd v230), while CVE-2018-16865
was introduced in December 2011 (systemd v38) and became
exploitable in April 2013 (systemd v201), Qualys says.

However, the third vulnerability (CVE-2018-16866) was introduced
in systemd’s codebase in June 2015 (systemd v221), but according to
the researchers, it was “inadvertently fixed in August 2018.”

If you are using a vulnerable Linux system, keep tabs on the
latest updates by your respective Linux distribution and install
the patches as soon as they are released.

^[1]^[2]

References

^{^}
Redhat
(access.redhat.com)
^{^}
Debian
(security-tracker.debian.org)
^{^}
-fstack-clash-protection
(gcc.gnu.org)
^{^}
advisory
(www.qualys.com)

The Hacker News Headlines

New Apple iOS 16 Exploit Enables Stealthy Cellular Access Under Fake Airplane Mode

Aug 18, 2023

The Hacker News Headlines

China-Linked Bronze Starlight Group Targeting Gambling Sector with Cobalt Strike Beacons

Aug 18, 2023

The Hacker News Headlines

NoFilter Attack: Sneaky Privilege Escalation Method Bypasses Windows Security

Aug 18, 2023

OWASP TOP !0

Injection. Injection flaws, such as SQL, NoSQL, OS, and LDAP injection, occur when untrusted data is sent to an interpreter as part of a command or query. The attacker’s hostile data can trick the interpreter into executing unintended commands or accessing data without proper authorization. Broken Authentication. Application functions related to authentication and session management are often implemented incorrectly, allowing attackers to compromise passwords, keys, or session tokens, or to exploit other implementation flaws to assume other users’ identities temporarily or permanently. Sensitive Data Exposure. Many web applications and APIs do not properly protect sensitive data, such as financial, healthcare, and PII. Attackers may steal or modify such weakly protected data to conduct credit card fraud, identity theft, or other crimes. Sensitive data may be compromised without extra protection, such as encryption at rest or in transit, and requires special precautions when exchanged with the browser. XML External Entities (XXE). Many older or poorly configured XML processors evaluate external entity references within XML documents. External entities can be used to disclose internal files using the file URI handler, internal file shares, internal port scanning, remote code execution, and denial of service attacks. Broken Access Control. Restrictions on what authenticated users are allowed to do are often not properly enforced. Attackers can exploit these flaws to access unauthorized functionality and/or data, such as access other users’ accounts, view sensitive files, modify other users’ data, change access rights, etc. Security Misconfiguration. Security misconfiguration is the most commonly seen issue. This is commonly a result of insecure default configurations, incomplete or ad hoc configurations, open cloud storage, misconfigured HTTP headers, and verbose error messages containing sensitive information. Not only must all operating systems, frameworks, libraries, and applications be securely configured, but they must be patched/upgraded in a timely fashion. Cross-Site Scripting XSS. XSS flaws occur whenever an application includes untrusted data in a new web page without proper validation or escaping, or updates an existing web page with user-supplied data using a browser API that can create HTML or JavaScript. XSS allows attackers to execute scripts in the victim’s browser which can hijack user sessions, deface web sites, or redirect the user to malicious sites. Insecure Deserialization. Insecure deserialization often leads to remote code execution. Even if deserialization flaws do not result in remote code execution, they can be used to perform attacks, including replay attacks, injection attacks, and privilege escalation attacks. Using Components with Known Vulnerabilities. Components, such as libraries, frameworks, and other software modules, run with the same privileges as the application. If a vulnerable component is exploited, such an attack can facilitate serious data loss or server takeover. Applications and APIs using components with known vulnerabilities may undermine application defenses and enable various attacks and impacts. Insufficient Logging & Monitoring. Insufficient logging and monitoring, coupled with missing or ineffective integration with incident response, allows attackers to further attack systems, maintain persistence, pivot to more systems, and tamper, extract, or destroy data. Most breach studies show time to detect a breach is over 200 days, typically detected by external parties rather than internal processes or monitoring.

New Systemd Privilege Escalation Flaws Affect Most Linux Distributions

References

Related Post

New Apple iOS 16 Exploit Enables Stealthy Cellular Access Under Fake Airplane Mode

China-Linked Bronze Starlight Group Targeting Gambling Sector with Cobalt Strike Beacons

NoFilter Attack: Sneaky Privilege Escalation Method Bypasses Windows Security

You missed

Protected: Rotary VI EAST

Protected: BetterCyberCareer Group

Protected: Benin Club 1931 – Official

Protected: Whatsapp AI Automation Group