Security Bulletin
Summary
The RC4 “Bar Mitzvah” Attack for SSL/TLS affects IBM Rational Directory Server and Administrator.
Vulnerability Details
CVEID: CVE-2015-2808
DESCRIPTION: The RC4 algorithm, as used in the TLS protocol and SSL protocol, could allow a remote attacker to obtain sensitive information. An attacker could exploit this vulnerability to remotely expose account credentials without requiring an active man-in-the-middle session. Successful exploitation could allow an attacker to retrieve credit card data or other sensitive information. This vulnerability is commonly referred to as "Bar Mitzvah Attack".
CVSS Base Score: 5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/101851 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:P/I:N/A:N)
Affected Products and Versions
|
Product | Version |
| Rational Directory Server (Tivoli) | 5.2 - 5.2.1_iFix006 |
| Rational Directory Server (Apache) | 5.1.1 - 5.1.1.2_iFix007 |
Remediation/Fixes
| Product | Download link |
| IBM Rational Directory Server 5.2 (Tivoli) and above | RDS 5.2.1 iFix07 |
| IBM Rational Directory Server 5.1.1 (Apache) and above | RDS 5.1.1.2 iFix08 |
NOTE: You should verify applying this fix does not cause any compatibility issues. The fix disables RC4 stream cipher by default. If you change this setting you 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.
For Rational Directory Server and Administrator, versions prior to 5.2 (Tivoli) and 5.1.1 (Apache) IBM recommends upgrading to supported version of the product.
Workarounds and Mitigations
For IBM Tivoli Directory Server, certain configuration changes are required to mitigate this issue.
1. Go to the tdsadmin Instance folder
- a. For Windows based system:
- Go to folder location C:\idsslapd-tdsadmin\etc
b. For UNIX based system:
- Go to folder location <RDS Install Location>/Instance/idsslapd-tdsadmin/etc
2. Take a backup of the file ibmslapd.conf
3. Open the file for editing.
4. Search for ibm-slapdSslCipherSpec
5. Under this attribute, comment all ciphers that start with RC4. Your sample ibmslapd.conf should look like this
- #ibm-slapdSslCipherSpec: RC4-128-MD5
#ibm-slapdSslCipherSpec: RC4-128-SHA
ibm-slapdSslCipherSpec: AES
ibm-slapdSslCipherSpec: AES-128
ibm-slapdSslCipherSpec: TripleDES-168
ibm-slapdSslCipherSpec: DES-56
#ibm-slapdSslCipherSpec: RC4-40-MD5
#ibm-slapdSslCipherSpec: RC2-40-MD5
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.
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References
Change History
27 April 2015 Original Version Published
*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.
Disclaimer
Review the IBM security bulletin disclaimer and definitions regarding your responsibilities for assessing potential impact of security vulnerabilities to your environment.
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Document Information
Modified date:
17 June 2018
UID
swg21882527