Security Bulletin
Summary
The RC4 "Bar Mitzvah Attack" for Secure Sockets Layer (SSL) and Transport Layer Security (TLS) affects z/TPF.
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
z/TPF Enterprise Edition Version 1.1.11 and earlier
Remediation/Fixes
|
Product | VRMF | APAR | Remediation/First Fix |
| z/TPF | 1.1.11 and earlier | None | Do not use the RC4 algorithm in SSL sessions. See Workarounds and Mitigations. |
Workarounds and Mitigations
Disable the RC4 encryption algorithm from the OpenSSL library for z/TPF. To disable the RC4 encryption algorithm, complete the following steps:
- Ensure that existing SSL applications are not set up to use the RC4 encryption alogorithm. If they are, change the applications to use a more secure algorithm, such as AES-128.
- Add the OPENSSL_NO_RC4 compiler option to the cryp.mak and cssl.mak files:
- In the cryp.mak file, add the following statement:
CFLAGS_CRYP += -DOPENSSL_NO_RC4 - In the cssl.mak file, add the following statement:
CFLAGS_CSSL += -DOPENSSL_NO_RC4 - Remove or comment out the following source segments in the cryp.mak file:
#C_SRC += rc4_enc.c
#C_SRC += rc4_skey.c - Build the CRYP and CSSL shared objects by using maketpf with the force (-f) option
- Load the CRYP and CSSL shared objects to the z/TPF system again.
- Recyle the shared SSL daemons (if defined) and restart all SSL applications.
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References
Change History
10 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:
02 August 2018
UID
swg21702144