Disabling weak ciphers using port 1813 in RSA Authentication Manager 8.3 patch 1
2 years ago
Originally Published: 2018-08-07
Article Number
000067170
Applies To
Legacy block ciphers having a block size of 64 bits are vulnerable to a practical collision attack when used in CBC mode. All versions
of the SSL/TLS protocols that support cipher suites which use 3DES as the symmetric encryption cipher are affected. The security of a
block cipher is often reduced to the key size k: the best attack should be the exhaustive search of the key, with complexity 2 to the
power of k. However, the block size n is also an important security parameter, defining the amount of data that can be encrypted under
the same key. This is particularly important when using common modes of operation: we require block ciphers to be secure with up to 2
to the power of n queries, but most modes of operation (e.g. CBC, CTR, GCM, OCB, etc.) are unsafe with more than 2 to the power of
half n blocks of message (the birthday bound). With a modern block cipher with 128-bit blocks such as AES, the birthday bound
corresponds to 256 exabytes. However, for a block cipher with 64-bit blocks, the birthday bound corresponds to only 32 GB, which is
easily reached in practice. Once a collision between two cipher blocks occurs it is possible to use the collision to extract the plain text
data.
Affected Nodes:
Affected Nodes: Additional Information:
10.216.34.117:1813
(cho2x9aa01.corp.transunion.com)
Negotiated with the following insecure cipher suites: TLS 1.2 ciphers:
TLS_RSA_WITH_3DES_EDE_CBC_SHA

TLS/SSL Server Supports RC4 Cipher Algorithms (CVE-2013-2566) (rc4-cve-2013-2566)
Description:
Recent cryptanalysis results exploit biases in the RC4 keystream to recover repeatedly encrypted plaintexts. As a result, RC4 can no
longer be seen as providing a sufficient level of security for SSL/TLS sessions. It has many single-byte biases, which makes it easier for
remote attackers to conduct plaintext-recovery attacks via statistical analysis of ciphertext in a large number of sessions that use the
same plaintext.
Affected Nodes:
Affected Nodes: Additional Information:
10.216.34.117:1813
(cho2x9aa01.corp.transunion.com)
Negotiated with the following insecure cipher suites: TLS 1.2 ciphers:
TLS_RSA_WITH_RC4_128_MD5TLS_RSA_WITH_RC4_128_SHA

TLS/SSL Server Supports RC4 Cipher Algorithms (CVE-2013-2566) (rc4-cve-2013-2566)
Description:
Recent cryptanalysis results exploit biases in the RC4 keystream to recover repeatedly encrypted plaintexts. As a result, RC4 can no
longer be seen as providing a sufficient level of security for SSL/TLS sessions. It has many single-byte biases, which makes it easier for
remote attackers to conduct plaintext-recovery attacks via statistical analysis of ciphertext in a large number of sessions that use the
same plaintext.
Affected Nodes:
Affected Nodes: Additional Information:
10.216.34.117:1813
(cho2x9aa01.corp.transunion.com)
Negotiated with the following insecure cipher suites: TLS 1.2 ciphers:
TLS_RSA_WITH_RC4_128_MD5TLS_RSA_WITH_RC4_128_SHA

TLS/SSL Server Supports The Use of Static Key Ciphers (ssl-static-key-ciphers)
Description:
The server is configured to support ciphers known as static key ciphers. These ciphers don't support "Forward Secrecy". In the new
specification for HTTP/2, these ciphers have been blacklisted.
Affected Nodes:
Affected Nodes: Additional Information:
10.216.34.117:443
(cho2x9aa01.corp.transunion.com)
Negotiated with the following insecure cipher suites: TLS 1.2 ciphers:
TLS_RSA_WITH_AES_256_GCM_SHA384
10.216.34.117:1813
(cho2x9aa01.corp.transunion.com)
Negotiated with the following insecure cipher suites: TLS 1.2 ciphers:
TLS_DH_anon_WITH_AES_128_CBC_SHA256
TLS_DH_anon_WITH_AES_128_GCM_SHA256
TLS_DH_anon_WITH_AES_256_CBC_SHA
TLS_DH_anon_WITH_AES_256_GCM_SHA384
TLS_RSA_WITH_3DES_EDE_CBC_SHA
TLS_RSA_WITH_AES_128_CBC_SHA

TLS/SSL Server Supports 3DES Cipher Suite (ssl-3des-ciphers)
Description:
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.
Affected Nodes:
Affected Nodes: Additional Information:
10.216.34.117:1813
(cho2x9aa01.corp.transunion.com)
Negotiated with the following insecure cipher suites: TLS 1.2 ciphers:
TLS_RSA_WITH_3DES_EDE_CBC_SHA
CVE Identifier(s)
CVE-2016-2183
Article Summary
Weak ciphers were reported on ports 22, 443, 7002, 1812 and 1813. By editing the configuration file /opt/rsa/am/server/config/config.xml, we are able to remediate the weak ciphers on all ports except 1813. This article provides assistance in disabling the weak ciphers on port 1813. The flaw exists but not exploitable. 
Resolution
The RSA Authentication Manager 8.33 full installation kit (not the upgrade kit) is shipped with the sbr_administration.xml file without weaker ciphers. Replacing the file will resolve this issue. Contact RSA Support to obtain the correct sbr_administration.xml file.
  1. Launch an SSH client, such as PuTTy.
  2. Login to the primary Authentication Manager server as rsaadmin and enter the operating system password.

Note that during Quick Setup another user name may have been selected. Use that user name to login.

  1. Navigate to /opt/rsa/am/radius and list the file:
# cd /opt/rsa/am/radius
#​ ls -al sbr_administration.xml
-rw-r----- 1 rsaadmin rsaadmin 11775 Apr 18  2017 sbr_administration.xml
  1. Rename the existing file
# mv sbr_administration.xml sbr_administration.orig
  1. Copy the sbr_administration.xml  file obtained from RSA Support to /opt/rsa/am/radius using WinSCP or another secure copy client.
  2. Restart the RADIUS service
# cd /opt/rsa/am/server
./rsaserv restart radius
  1. Repeat steps 1 through 6 on each replica, doing the process on only one at a time.
Disclaimer
Read and use the information in this RSA Security Advisory to assist in avoiding any situation that might arise from the problems described herein. If you have any questions regarding this product alert, contact RSA Software Technical Support at 1- 800 995 5095. RSA Security LLC and its affiliates, including without limitation, its ultimate parent company, Dell EMC, distributes RSA Security Advisories in order to bring to the attention of users of the affected RSA products, important security information. RSA recommends that all users determine the applicability of this information to their individual situations and take appropriate action. The information set forth herein is provided 'as is' without warranty of any kind. RSA disclaims all warranties, either express or implied, including the warranties of merchantability, fitness for a particular purpose, title and non-infringement. In no event, shall RSA, its affiliates or suppliers, be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if RSA, its affiliates or suppliers have been advised of the possibility of such damages. Some jurisdictions do not allow the exclusion or limitation of liability for consequential or incidental damages, so the foregoing limitation may not apply.

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