A privileged attacker can exploit certain operation to execute arbitrary commands with root privileges, leading to full device compromise. An authenticated user can exploit gRPC Network Security Interface (gNSI) Certz service on Arista EOS-based products to escalate privileges and execute arbitrary OS commands via a crafted Certz Rotate request. The Bootz service is also affected.
For the Certz service to be exploitable, gNSI Certz must be enabled on the device. This can be verified with:
switch#show man api gnsi
Certz enabled: yes
For the Bootz service to be exploitable, Bootz must be used for initial provisioning and a CertzProfile containing X509 PEM certificates must be included.
For the Bootz service:
- Do not include X509 PEM certificates in the initial CertzProfile during Bootz provisioning.
For the Certz service (choose one):
Option 1: Disable gNSI Certz entirely (requires manual SSL profile management going forward):
switch(config)#management api gnsi
switch(config-mgmt-api-gnsi)#no service certz
Option 2: Restrict Certz access using a gNSI Authz policy. Apply an authorization policy that limits the Certz Rotate RPC to only explicitly permitted users:
switch(config)#management api gnsi
switch(config-mgmt-api-gnsi)#service authz
To detect potential exploitation, configure auditd to monitor for suspicious child processes spawned by OpenConfig/Octa services:
switch(config)#monitor security audit
switch(config-audit)#rule group process-creation
-a always,exit -F arch=b64 -S execve -k process-create
-a always,exit -F arch=b32 -S execve -k process-create
EOF
switch(config-audit)#monitor group process-creation
The following EOS releases contain the fix for this vulnerability:
- 4.33.9M and later releases in the 4.33.x train
- 4.34.7.1M and later releases in the 4.34.x train
- 4.35.6M and later releases in the 4.35.x train
- 4.36.1F and later releases in the 4.36.x train
No hotfix is available for this vulnerability.