Off-by-one in Botan - CVE-2018-9860
Published: April 12, 2018 / Updated: August 3, 2020
Vulnerability identifier: #VU33003
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2018-9860
CWE-ID: CWE-193
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Randombit
Affected software:
Botan
Botan
Detailed vulnerability description
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
An issue was discovered in Botan 1.11.32 through 2.x before 2.6.0. An off-by-one error when processing malformed TLS-CBC ciphertext could cause the receiving side to include in the HMAC computation exactly 64K bytes of data following the record buffer, aka an over-read. The MAC comparison will subsequently fail and the connection will be closed. This could be used for denial of service. No information leak occurs.
How to mitigate CVE-2018-9860
Install update from vendor's website.