Flashes (Alerts)
Abstract
With the recent attention to RC4 “Bar Mitzvah” Attack for SSL/TLS, IBM recommends to disable RC4 in DataPower's ISAM Proxy Module.
Content
Upgrade the DataPower appliance firmware to version 7.1.0.5. Additionally, ensure RC4 ciphers are disabled in DataPower configuration referring to the steps below.
1. First, make sure you apply patches to your IBM Security Access Manager Appliance hosting the Policy Server. These steps are described in the security bulletin CVE-2015-2808 (http://www-01.ibm.com/support/docview.wss?uid=swg21902389) for IBM Security Access Manager.
2. Next, make sure to Quiesce all domains and services to stop traffic to the appliance. System quiesce and unquiesce commands can be invoked by navigating to Administration --> Main --> System Control.
3. Next, for all domains where Security Access Manager objects are enabled, disable RC4 ciphers associated with Access Manager Runtime connection to LDAP. Edit the ldap.conf as follows:
select Objects -> Security Access Manager -> Access Manager Runtime -> Manage Files -> Edit ldap.conf
Configure the following entries to use one or more of the ciphers listed in the tables at the end of this tech note.
[ldap]
ssl-tls-cipher-specs
tls-v12-cipher-specs
Note: Ensure that you remove any references to the following cipher numbers -
01 02 03 04 05 06 09 62 64
[uraf-registry]
ssl-tls-cipher-specs
tls-v12-cipher-specs
Note: Ensure that you remove any references to the following ciphers:
TLS_RSA_WITH_RC4_128_SHA
TLS_RSA_WITH_RC4_128_MD5
TLS_RSA_WITH_DES_CBC_SHA
TLS_RSA_EXPORT_WITH_RC4_40_MD5
TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5
TLS_RSA_EXPORT1024_WITH_DES_CBC_SHA
TLS_RSA_EXPORT1024_WITH_RC4_56_SHA
TLS_RSA_WITH_NULL_SHA
TLS_RSA_WITH_NULL_MD5
TLS_RSA_WITH_NULL_SHA256
TLS_ECDHE_RSA_WITH_NULL_SHA
TLS_ECDHE_ECDSA_WITH_NULL_SHA
4. For all domains where Security Access Manager objects are enabled, disable RC4 ciphers associated with Access Manager Reverse Proxy instances. Edit each reverse proxy webseal.conf file as follows:
select Objects -> Security Access Manager -> Access Manager Reverse Proxy -> Manage Files -> Edit Configuration File
Under the [ssl] stanza, remove all references to RC4 ciphers from both the gsk_attr_name and the jct_gsk_attr_name attributes:
Long Name
-----------------------------------
TLS_RSA_WITH_RC4_128_SHA
TLS_RSA_WITH_RC4_128_MD5
TLS_RSA_WITH_DES_CBC_SHA
TLS_RSA_EXPORT_WITH_RC4_40_MD5
TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5
TLS_RSA_EXPORT1024_WITH_DES_CBC_SHA
TLS_RSA_EXPORT1024_WITH_RC4_56_SHA
TLS_RSA_WITH_NULL_SHA
TLS_RSA_WITH_NULL_MD5
TLS_RSA_WITH_NULL_SHA256
TLS_ECDHE_RSA_WITH_NULL_SHA
TLS_ECDHE_ECDSA_WITH_NULL_SHA
Note - Any instance of the above ciphers should be removed. Configure your environment to use one or more of the ciphers listed in the tables at the end of this tech note.
If the ssl-qop-mgmt attribute is set to “Yes” or "True", configure the default configuration entries in the [ssl-qop-mgmt-default] stanza to ensure that vulnerable ciphers are removed.
Note: Do not use a setting of 'ALL'.
Ensure that the following ciphers are not present in the configured ciphers:
default = RC4-40
default = RC2-40
default = DES-56
default = DES-56-62
default = RC4-56
default = RC4-128
default = RC2-128
If not already set, set the following attribute and values under the [ssl] stanza -
gsk-attr-name = enum:471:0
jct-gsk-attr-name = enum:471:0
Note - If these attributes are already set to then this can remain in place. It should not have any affect for the mitigation plan.
You should verify applying this configuration change does not cause any compatibility issues. Not disabling the RC4 stream cipher will expose yourself to the attack described above. IBM recommends that you review your entire environment to identify other areas where you have enabled the RC4 stream cipher and take appropriate mitigation and remediation actions.
Additional Information
The following ciphers remain valid:
For SSLv3, TLSv10, TLSv11
| TLS_RSA_WITH_3DES_EDE_CBC_SHA | 0A |
| TLS_RSA_WITH_AES_128_CBC_SHA | 2F |
| TLS_RSA_WITH_AES_256_CBC_SHA | 35 |
For TLSv12
| Long name |
| TLS_RSA_WITH_AES_128_GCM_SHA256 |
| TLS_RSA_WITH_AES_256_GCM_SHA384 |
| TLS_RSA_WITH_AES_128_CBC_SHA256 |
| TLS_RSA_WITH_AES_256_CBC_SHA256 |
| TLS_RSA_WITH_AES_128_CBC_SHA |
| TLS_RSA_WITH_AES_256_CBC_SHA |
| TLS_RSA_WITH_3DES_EDE_CBC_SHA |
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA |
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA |
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 |
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 |
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 |
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 |
| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 |
| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 |
| TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 |
| TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 |
Related Information
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Document Information
Modified date:
25 September 2022
UID
swg21960889