On October 31, 2016 (local time), Cisco Talos published three integer overflow vulnerabilities with the Memcached server on its official website http://www.talosintelligence.com.
The vulnerability assigned CVE-2016-8704 was found in the process_bin_append_prepend function. CVE-2016-8705 is about an integer overflow in the process_bin_update function. The last vulnerability, namely CVE-2016-8706, has been confirmed to be associated with the process_bin_sasl_auth function. All these vulnerabilities could be exploited to cause a heap overflow, leading to remote code execution.
For details, click the following links:
http://www.talosintelligence.com/reports/TALOS-2016-0219/
http://www.talosintelligence.com/reports/TALOS-2016-0220/
http://www.talosintelligence.com/reports/TALOS-2016-0221/
For the official release notes regarding fixes for these vulnerabilities, visit the following link:
https://github.com/memcached/memcached/wiki/ReleaseNotes1433
What Is Memcached?
Memcached is a high-performance, distributed memory object caching system for speeding up dynamic web applications by alleviating database load. Specifically, it speeds up dynamic database-driven websites by caching data and objects in RAM to reduce the number of times an external data source must be read. Memcached is a hashmap of key-value pairs. Its daemon is written in C, but the client can be written in any languages and communicates with the daemon via the memcached protocol.
Alert Level Graded by NSFOCUS
High-level: With an extensive scope of impact and a potential for serious damage, the threat is comparatively easy to exploit. For such threats, NSFOCUS should initiate the 24/7 emergency handling mechanism and complete technical analysis, upgrade related products, and produce appropriate solutions within 24 hours.
Affected Versions
- Memcached version < 1.4.33
Unaffected Versions
- Memcached version = 1.4.33
Fixes
The vendor has released an update. Users are advised to upgrade Memcached to the latest version by downloading the update from the vendor’s official website:
NSFOCUS’s security team will keep a close eye on the dynamics of the event. Our follow-ups also include releasing a detailed analysis report and providing more details about product upgrade and solutions.
NSFOCUS’s Criteria for Grading Security Threats
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| Level | Description |
| High | With an extensive scope of impact and a potential for serious damage, the threat is comparatively easy to exploit. For such threats, NSFOCUS should initiate the 24/7 emergency handling mechanism and complete technical analysis, upgrade related products, and produce appropriate solutions within 24 hours. |
| Medium | With a controllable scope of impact and controllable potential damage, the threat is comparatively difficult to exploit. For such threats, NSFOCUS should initiate the 7×8 (8 hours a day, 7 days a week) emergency handling mechanism and complete technical analysis, upgrade related products, and produce appropriate solutions within 72 hours. |
| Low | With a limited scope of impact and limited degree of damage. |
Statement
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This advisory is only used to describe a potential risk. NSFOCUS does not provide any commitment or promise on this advisory. NSFOCUS and the author will not bear any liability for any direct and/or indirect consequences and losses caused by transmitting and/or using this advisory. NSFOCUS reserves all the rights to modify and interpret this advisory. Please include this statement paragraph when reproducing or transferring this advisory. Do not modify this advisory, add/delete any information to/from it, or use this advisory for commercial purposes without permission from NSFOCUS.
About NSFOCUS
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NSFOCUS IB is a wholly owned subsidiary of NSFOCUS, an enterprise application and network security provider, with operations in the Americas, Europe, the Middle East, Southeast Asia and Japan. NSFOCUS IB has a proven track record of combatting the increasingly complex cyber threat landscape through the construction and implementation of multi-layered defense systems. The company’s Intelligent Hybrid Security strategy utilizes both cloud and on-premises security platforms, built on a foundation of real-time global threat intelligence, to provide unified, multi-layer protection from advanced cyber threats.
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