
Script do Zeek e regras do Suricata para detectar a exploração do PrintNightmare (CVE-2021-1675) por meio de eventos DCE RPC do RpcAddPrinterDriver, com testes baseados em PCAP.
Este script Zeek detecta eventos DCE RPC bem-sucedidos de RpcAddPrinterDriver{,Ex}, que são necessários para explorar a vulnerabilidade com sucesso. Os testes são baseados no PCAP de exploração do Lares Lab. Testado com as versões do Zeek 3.0.2 e 4.0.1.
Printer_Driver_Changed_Successfully indica que o driver de impressora foi alterado com sucesso.Também fornecemos regras do Suricata para detectar os comandos DCE RPC usados nesta exploração. Elas podem ser carregadas em um appliance Corelight ou executadas diretamente com o Suricata. Essas regras disparam muito em redes maiores e podem ser suficientemente ruidosas a ponto de não serem úteis. Use com cautela. Nós as mantivemos aqui caso sejam úteis em outras redes. Em nossa opinião, o pacote Zeek é mais robusto contra ruído.
A saída da execução do Suricata com o conjunto de regras fornecido é mostrada abaixo:
$ suricata -r testing/Traces/PrintNightmare.pcap -S suricata.rules
8/7/2021 -- 10:54:57 - <Notice> - This is Suricata version 6.0.3 RELEASE running in USER mode
8/7/2021 -- 10:54:57 - <Warning> - [ERRCODE: SC_WARN_ERSPAN_CONFIG(329)] - ERSPAN Type I is no longer configurable and it is always enabled; ignoring configuration setting.
8/7/2021 -- 10:54:57 - <Notice> - all 17 packet processing threads, 4 management threads initialized, engine started.
8/7/2021 -- 10:54:57 - <Notice> - Signal Received. Stopping engine.
8/7/2021 -- 10:54:57 - <Notice> - Pcap-file module read 1 files, 53 packets, 19124 bytes
$ cat fast.log
07/02/2021-08:11:57.785982 [**] [1:3000007:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriver [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:11:57.824060 [**] [1:3000007:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriver [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:11:57.848240 [**] [1:3000007:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriver [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:11:57.848240 [**] [1:3000008:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriverEx [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:11:57.894097 [**] [1:3000007:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriver [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:11:57.894097 [**] [1:3000008:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriverEx [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:11:57.959051 [**] [1:3000007:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriver [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:11:57.959051 [**] [1:3000008:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriverEx [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:11:58.000581 [**] [1:3000007:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriver [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:11:58.000581 [**] [1:3000008:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriverEx [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:11:58.007953 [**] [1:3000007:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriver [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:12:08.520328 [**] [1:3000007:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriver [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445
07/02/2021-08:12:08.520328 [**] [1:3000008:2] CORELIGHT Possible CVE-2021-34527 (PrintNightmare) Exploit - SpoolSS RpcAddPrinterDriverEx [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 192.168.1.149:50070 -> 192.168.1.157:445