An issue was discovered on NOKIA Airscale ASIKA Single RAN devices before 21B. Nokia Single RAN commissioning procedures do not change (factory-time installed) default SSH public/private key values that are specific to a network operator. As a result, the CSP internal BTS network SSH server (disabled by default) continues to apply the default SSH public/private key values. These keys don't give access to BTS, because service user authentication is username/password-based on top of SSH. Nokia factory installed default SSH keys are meant to be changed from operator-specific values during the BTS deployment commissioning phase. However, before the 21B release, BTS commissioning manuals did not provide instructions to change default SSH keys (to BTS operator-specific values). This leads to a possibility for malicious operations staff (inside a CSP network) to attempt MITM exploitation of BTS service user access, during the moments that SSH is enabled for Nokia service personnel to perform troubleshooting activities.
References
An issue was discovered on NOKIA Airscale ASIKA Single RAN devices before 21B. Nokia Single RAN commissioning procedures do not change (factory-time installed) default SSH public/private key values that are specific to a network operator. As a result, the CSP internal BTS network SSH server (disabled by default) continues to apply the default SSH public/private key values. These keys don't give access to BTS, because service user authentication is username/password-based on top of SSH. Nokia factory installed default SSH keys are meant to be changed from operator-specific values during the BTS deployment commissioning phase. However, before the 21B release, BTS commissioning manuals did not provide instructions to change default SSH keys (to BTS operator-specific values). This leads to a possibility for malicious operations staff (inside a CSP network) to attempt MITM exploitation of BTS service user access, during the moments that SSH is enabled for Nokia service personnel to perform troubleshooting activities.
References