CVE-2021-33910 – systemd: uncontrolled allocation on the stack in function unit_name_path_escape leads to crash

https://notcve.org/view.php?id=CVE-2021-33910

basic/unit-name.c in systemd prior to 246.15, 247.8, 248.5, and 249.1 has a Memory Allocation with an Excessive Size Value (involving strdupa and alloca for a pathname controlled by a local attacker) that results in an operating system crash. basic/unit-name.c en systemd anterior a las versiones 246.15, 247.8, 248.5 y 249.1 tiene una asignación de memoria con un valor de tamaño excesivo (que involucra a strdupa y alloca para un nombre de ruta controlado por un atacante local) que resulta en una caída del sistema operativo A flaw was found in systemd. The use of alloca function with an uncontrolled size in function unit_name_path_escape allows a local attacker, able to mount a filesystem on a very long path, to crash systemd and the whole system by allocating a very large space in the stack. The highest threat from this vulnerability is to the system availability. • http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html http://www.openwall.com/lists/oss-security/2021/08/04/2 http://www.openwall.com/lists/oss-security/2021/08/17/3 http://www.openwall.com/lists/oss-security/2021/09/07/3 https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce • CWE-400: Uncontrolled Resource Consumption CWE-770: Allocation of Resources Without Limits or Throttling •