SB2018122512 - Cache Attacks in mbedtls (Alpine package)
Published: December 25, 2018
Security Bulletin ID
SB2018122512
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Cache Attacks (CVE-ID: CVE-2018-19608)
The vulnerability allows a remote attacker to perform a downgrade attack on the server and decrypt private keys on the target system.The vulnerability exists due to a core weakness in TLS that relates to the handshaking of the session key which is used within the tunnel during parallelisation of thousands of oracle queries that occurs using a cluster of TLS servers which share the same public key certificate. A remote attacker can mount a microarchitectural side channel attack against a vulnerable implementation, obtain a network man-in-the-middle position, obtain the relevant data to sign and trigger the victim server to decrypt ciphertexts chosen by the adversary to perform a downgrade attack.
Remediation
Install update from vendor's website.
References
- https://git.alpinelinux.org/aports/commit/?id=7c957c41625c408c47ca8aa93fd986ac6fec39a2
- https://git.alpinelinux.org/aports/commit/?id=c087d07fafa8d964c90795fd34c46fda72a152a4
- https://git.alpinelinux.org/aports/commit/?id=f0377de9384c6b80e8d69a847c1c2450f68f50da
- https://git.alpinelinux.org/aports/commit/?id=12f88f964ce5637e0f8cbe1b8eb8119a52d2eac7