CVE-2020-15704 : Exploit Details and Defense Strategies
Discover the impact of CVE-2020-15704, an information disclosure vulnerability in pppd. Learn about affected versions, exploitation risks, and mitigation steps to secure your systems.
A vulnerability in pppd could allow a local non-root attacker to read arbitrary root files. This CVE was discovered by Thomas Chauchefoin working with Trend Micro's Zero Day Initiative.
Understanding CVE-2020-15704
This CVE involves an information disclosure vulnerability in pppd, affecting specific versions of the software.
What is CVE-2020-15704?
The modprobe child process in the ./debian/patches/load_ppp_generic_if_needed patch file mishandles module loading, enabling a local non-root attacker to exploit the MODPROBE_OPTIONS environment variable to access arbitrary root files.
The Impact of CVE-2020-15704
The vulnerability has a CVSS base score of 5.5, indicating a medium severity issue with high confidentiality impact but low privileges required for exploitation.
Technical Details of CVE-2020-15704
This section provides more in-depth technical insights into the vulnerability.
Vulnerability Description
The modprobe child process in the ./debian/patches/load_ppp_generic_if_needed patch file incorrectly handles module loading, leading to the information disclosure vulnerability.
Affected Systems and Versions
- Versions 2.4.5 and 2.4.7 of ppp are affected.
- Specifically, versions 2.4.5-5ubuntu1.4, 2.4.5-5.1ubuntu2.3+esm2, 2.4.7-1+2ubuntu1.16.04.3, 2.4.7-2+2ubuntu1.3, 2.4.7-2+4.1ubuntu5.1, and 2.4.7-2+4.1ubuntu6 are vulnerable.
Exploitation Mechanism
The vulnerability can be exploited by a local non-root attacker manipulating the MODPROBE_OPTIONS environment variable to gain unauthorized access to root files.
Mitigation and Prevention
Protecting systems from CVE-2020-15704 involves immediate actions and long-term security practices.
Immediate Steps to Take
- Apply the necessary patches provided by the vendor.
- Monitor for any unauthorized access attempts.
Long-Term Security Practices
- Regularly update software to the latest versions.
- Implement least privilege access controls.
Patching and Updates
- Canonical has released patches for the affected versions of ppp. Ensure all systems are updated with the latest patches.