CVE Vulnerabilities

CVE-2020-36423

Cleartext Transmission of Sensitive Information

Published: Jul 19, 2021 | Modified: Jan 11, 2023
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a certain Lucky 13 countermeasure doesnt properly consider the case of a hardware accelerator.

Weakness

The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.

Affected Software

Name Vendor Start Version End Version
Mbed_tls Arm * 2.16.7 (excluding)
Mbed_tls Arm 2.17.0 (including) 2.23.0 (excluding)
Mbedtls Ubuntu bionic *
Mbedtls Ubuntu groovy *
Mbedtls Ubuntu hirsute *
Mbedtls Ubuntu impish *
Mbedtls Ubuntu kinetic *
Mbedtls Ubuntu lunar *
Mbedtls Ubuntu mantic *
Mbedtls Ubuntu trusty *
Mbedtls Ubuntu xenial *

Extended Description

Many communication channels can be “sniffed” (monitored) by adversaries during data transmission. For example, in networking, packets can traverse many intermediary nodes from the source to the destination, whether across the internet, an internal network, the cloud, etc. Some actors might have privileged access to a network interface or any link along the channel, such as a router, but they might not be authorized to collect the underlying data. As a result, network traffic could be sniffed by adversaries, spilling security-critical data. Applicable communication channels are not limited to software products. Applicable channels include hardware-specific technologies such as internal hardware networks and external debug channels, supporting remote JTAG debugging. When mitigations are not applied to combat adversaries within the product’s threat model, this weakness significantly lowers the difficulty of exploitation by such adversaries. When full communications are recorded or logged, such as with a packet dump, an adversary could attempt to obtain the dump long after the transmission has occurred and try to “sniff” the cleartext from the recorded communications in the dump itself.

Potential Mitigations

References