Published on August 2nd, 2017 | Last Update: August 2nd, 2017



A vulnerability scan of the ACOS management interface indicated that the HTTPS service supported TLS sessions using ciphers based on the 3DES algorithm which is no longer considered capable of providing a sufficient level of security in SSL/TLS sessions. CVE-2016-2183 is a commonly referenced CVEs for this issue. Accordingly, the following vulnerabilities are addressed in this document.

Item Score
# Vulnerability ID Source Score Summary
1 ssl-3des-ciphers Rapid7 1 Moderate TLS/SSL Server Supports 3DES Cipher Suite [1]
2 CVE-2016-2183 CVSS 3.0 5.3 Medium SWEET32 Mitigation - OpenSSL [2]


Affected Releases

The table below indicates releases of ACOS exposed to these vulnerabilities and ACOS releases that address these issues or are otherwise unaffected by them.

Customers using affected ACOS releases can overcome vulnerability exposures by updating to the indicated resolved release. If the table does not list a corresponding resolved or unaffected release, then no ACOS release update is currently available.

Releases Affected Releases Resolved or Unaffected
  4.1.2, 4.1.1 (a)
4.1.0 – 4.1.0-P7 4.1.0-P8
3.1.0-P1 – 3.1.4 3.1.4-P1
3.2.0 – 3.2.1-P1 3.2.2-P1
2.8.2 – 2.8.2-P8 2.8.2-P9 (b), 4.1.2 (a, c)
2.7.2 – 2.7.2-P10 2.7.2-P11 (b), 4.1.0-P8 (c), 4.1.1 (a, c)
2.7.1-GR1 – 2.7.1-GR1-P1 2.7.2-P11 (b), 4.1.0-P8 (c), 4.1.1 (a, c)
2.6.1-GR1 – 2.6.1-GR1-P16 2.7.2-P11 (b), 4.1.0-P8 (c), 4.1.1 (a, c)

(a) Including all updates to the release(s).
(b) Partial Remediation. Expanded cipher suite supported, including 3DES cipher.
(c) Full Remediation. Expanded cipher suite supported, excluding 3DES cipher.

With the 2.7.2 and 2.8.2 resolved releases, the ACOS HTTPS management service additionally supports ciphers that include RSA, ECDHE-RSA, ECDHE-ECDSA, AES, and AES-GCM capabilities. These releases continue to support the 3DES cipher to avoid impacting existing deployment environments with management applications dependent on this cipher.

To fully overcome vulnerability exposures due to the 3DES cipher, the ACOS 4.1 resolved or unaffected releases are available for upgrade.



Common security best practices in the industry for network appliance management and control planes can enhance protection against remote malicious attacks. Limit the exploitable attack surface for critical, infrastructure, networking equipment through the use of access lists or firewall filters to and from only trusted, administrative networks or hosts.



Software updates that address these vulnerabilities are or will be published at the following URL:



The following table shares brief descriptions for the vulnerabilities addressed in this document.

Vulnerability ID Description
ssl-3des-ciphers   Transport Layer Security (TLS) versions 1.0 (RFC 2246) and 1.1 (RFC 4346) include cipher suites based on the 3DES (Triple Data Encryption Standard) algorithm. Since 3DES only provides an effective security of 112 bits, it is considered close to end of life by some agencies. Consequently, the 3DES algorithm is not included in the specifications for TLS version 1.3. ECRYPT II (from 2012) recommends for generic application independent long-term protection at least 128 bits security. The same recommendation has also been reported by BSI Germany (from 2015) and ANSSI France (from 2014), 128 bit is the recommended symmetric size and should be mandatory after 2020. While NIST (from 2012) still considers 3DES being appropriate to use until the end of 2030.
CVE-2016-2183   The DES and Triple DES ciphers, as used in the TLS, SSH, and IPSec protocols and other protocols and products, have a birthday bound of approximately four billion blocks, which makes it easier for remote attackers to obtain cleartext data via a birthday attack against a long-duration encrypted session, as demonstrated by an HTTPS session using Triple DES in CBC mode, aka a "Sweet32" attack.



Ref # General Link
[1] Rapid7: TLS/SSL Server Supports 3DES Cipher Algorithms
[2] NIST NVD, CVE-2016-2183
[3] NIST CSRC - Update to Current Use and Deprecation of TDEA






Revision Date Description
1.0 2017-08-02 Initial Publication
Wednesday, August 2, 2017