1. A computer-implemented method for decrypting network traffic on a middlebox device using a trusted execution environment, at least a portion of the method being performed by the middlebox device comprising one or more processors, the method comprising: (a) initializing the trusted execution environment (TEE); (b) loading a kernel application inside the TEE and a sensitivity policy inside the TEE; (c) sending, to a client device or a server device, attestation that the kernel application inside the TEE is authentic; (d) receiving at the kernel application inside the TEE, from the client device or the server device, a symmetric session key of an encrypted network session between the client device and the server device; (e) loading a logic application outside the TEE; (f) intercepting, by the logic application, encrypted network traffic from the client device that is directed to the server device; (g) forwarding, from the logic application outside the TEE to the kernel application inside the TEE, the encrypted network traffic; (h) decrypting, at the kernel application inside the TEE, the encrypted network traffic using the symmetric session key; (i) inspecting, at the kernel application inside the TEE, the decrypted network traffic according to the sensitivity policy to determine whether the decrypted network traffic includes sensitive data; (j) in response to determining that the decrypted network traffic includes sensitive data, filtering the decrypted network traffic to exclude the sensitive data; (k) forwarding, from the kernel application inside the TEE to the logic application outside the TEE, the filtered decrypted network traffic; (l) processing, at the logic application outside the TEE, the filtered decrypted network traffic; (m) forwarding, from the logic application outside the TEE to the kernel application inside the TEE, the filtered decrypted network traffic after the processing by the logic application outside the TEE; (m.1) logging in a log, at the kernel application inside the TEE, the filtered decrypted network traffic that was forwarded to the logic application outside the TEE; (n) forwarding, from the kernel application inside the TEE, the encrypted network traffic to the server device; and (o) providing, from the kernel application inside the TEE, the log to the client device or to the server device.