(IBM Issues Fix) OpenSSL CMS_verify() Error Handling Flaw Lets Users Bypass Security Checks
SecurityTracker Alert ID: 1022200|
SecurityTracker URL: http://securitytracker.com/id/1022200
(Links to External Site)
Date: May 11 2009
Modification of system information|
Fix Available: Yes Vendor Confirmed: Yes |
Version(s): 0.9.8h - 0.9.8j|
A vulnerability was reported in OpenSSL. A remote user can bypass certain security checks.|
A remote user with access to a signer's private key can generate a specially crafted signature that is not valid but will be detected as valid. The vulnerability resides in the CMS_verify() function in the handling of an error condition with specially crafted signed attributes.
Only CMS users are affected.
Ivan Nestlerode reported this vulnerability.
A remote user can create an invalid signature that will be determined to be a valid signature.|
IBM has issued a fix for AIX (OpenSSL AIX version 0.9.8.803), available at:|
The IBM advisory is available at:
Vendor URL: www.openssl.org/news/secadv_20090325.txt (Links to External Site)
Authentication error, State error|
This archive entry is a follow-up to the message listed below.|
Source Message Contents
Date: Mon, 11 May 2009 15:45:58 -0400|
Subject: IBM AIX
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IBM SECURITY ADVISORY
First Issued: Mon May 11 10:36:12 CDT 2009
The most recent version of this document is available here:
VULNERABILITY: AIX OpenSSL 0.9.8.803 with Security Patches
PLATFORMS: AIX 5.2, 5.3, 6.1
SOLUTION: Apply the fix as described below.
THREAT: See below
CERT VU Number: n/a
CVE Numbers: CVE-2009-0590 CVE-2009-0591 CVE-2009-0789
Three moderate severity security flaws have been fixed in OpenSSL
0.9.8k. The AIX version number is 0.9.8.803.
The function ASN1_STRING_print_ex() when used to print a BMPString
or UniversalString will crash with an invalid memory access if the
encoded length of the string is illegal. (CVE-2009-0590)
The function CMS_verify() does not correctly handle an error
condition involving malformed signed attributes. This will cause
an invalid set of signed attributes to appear valid and content
digests will not be checked. (CVE-2009-0591)
When a malformed ASN1 structure is received it's contents are
freed up and zeroed and an error condition returned. On a small
number of platforms where sizeof(long) < sizeof(void *) (for
example WIN64) this can cause an invalid memory access later
resulting in a crash when some invalid structures are read, for
example RSA public keys (CVE-2009-0789).
For more information about the three flaws, please visit:
II. PLATFORM VULNERABILITY ASSESSMENT
To determine if your system is vulnerable, execute the following
lslpp -L openssl.base
The following fileset levels are vulnerable:
AIX 6.1: all versions less than 0.9.8.803
AIX 5.3: all versions less than 0.9.8.803
AIX 5.2: all versions less than 0.9.8.803
A fix is available, and it can be downloaded from:
There are no workarounds.
V. CONTACT INFORMATION
If you would like to receive AIX Security Advisories via email,
and click on the "My notifications" link.
To view previously issued advisories, please visit:
Comments regarding the content of this announcement can be
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