CVE-2016-8610
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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.
Additional information
- Bugzilla 1384743: SSL/TLS: Malformed plain-text ALERT packets could cause remote DoS
- FAQ: Frequently asked questions about CVE-2016-8610
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
| Red Hat | NVD | |
|---|---|---|
CVSS v3 Base Score | 7.5 | 7.5 |
Attack Vector | Network | Network |
Attack Complexity | Low | Low |
Privileges Required | None | None |
User Interaction | None | None |
Scope | Unchanged | Unchanged |
Confidentiality Impact | None | None |
Integrity Impact | None | None |
Availability Impact | High | High |
CVSS v3 Vector
Red Hat: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
| Red Hat | NVD | |
|---|---|---|
CVSS v2 Base Score | 4.3 | 5 |
Attack Vector | Network | Network |
Access Complexity | Medium | Low |
Authentication | None | None |
Confidentiality Impact | None | None |
Integrity Impact | None | None |
Availability Impact | Partial | Partial |
CVSS v2 Vector
Red Hat: AV:N/AC:M/Au:N/C:N/I:N/A:P
NVD: AV:N/AC:L/Au:N/C:N/I:N/A:P
Acknowledgements
Red Hat would like to thank Shi Lei (Gear Team of Qihoo 360 Inc.) for reporting this issue.
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
For more information, see https://access.redhat.com/solutions/762393.
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
- "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
- "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.
What can I do if my product is listed as "Will not fix"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
- Apply a mitigation (if one exists).
- Open a support case to request a prioritization of releasing a fix for this vulnerability.
What can I do if my product is listed as "Fix deferred"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Apply a mitigation (if one exists).
- Open a support case to request a prioritization of releasing a fix for this vulnerability.
- Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
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