CVE-2016-8610
SSL/TLS: Malformed plain-text ALERT packets could cause remote DoS
Severity
ModerateRed Hat Product Security
CVSS 3.0
Review impact separately from score.
Published · October 24, 2016
Updated · September 21, 2026
Description
A denial of service flaw was found in the way the TLS/SSL protocol defined processing of ALERT packets during a connection handshake. A remote attacker could use this flaw to make a TLS/SSL server consume an excessive amount of CPU and fail to accept connections from other clients.
Statement
This flaw affects applications that are compiled against OpenSSL or GnuTLS and do not allocate an extra thread for processing ClientHello messages. Nginx is affected by this issue; Apache httpd is not affected by this issue. This issue has been rated as having a security impact of Moderate. It requires an attacker to send a very large amount of SSL ALERT messages to the host network connection. This issue can also be mitigated by configuring firewalls to limit the number of connections per IP address, or use deep packet inspection to reject these type of alert packets. A future update may address this issue.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.0 · 7.5CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0 · 4.3AV:N/AC:M/Au:N/C:N/I:N/A:P
CWE not specified