Covert Timing Channel in mbed TLS - CVE-2025-49087
Published: July 7, 2025
Vulnerability identifier: #VU112443
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:N/SA:N]
CVE-ID: CVE-2025-49087
CWE-ID: CWE-385
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform MitM attack.
The vulnerability exists due to a timing side channel attack on its implementation of PKCS#7 padding removal. A remote attacker with access to timing information and a decryption oracle can recover the last byte of each plaintext block. If some portion of the plaintext is controlled by the attacker as is often the case, the whole plaintext can be recovered.
Affected software
mbed TLS
PowerVM Hypervisor
PowerVM Hypervisor
How to mitigate CVE-2025-49087
Install updates from vendor's website.
mbed TLS - update to 3.6.4
PowerVM Hypervisor - addressed in versions FW1060.52, FW1110.10
PowerVM Hypervisor - addressed in versions FW1060.52, FW1110.10