NSFOCUS SA2007-01 : Microsoft IE5 CSS Parsing Memory Corruption Vulnerability

2007-08-16T00:00:00
ID SECURITYVULNS:DOC:17809
Type securityvulns
Reporter Securityvulns
Modified 2007-08-16T00:00:00

Description

NSFOCUS Security Advisory (SA2007-01)

Microsoft IE5 CSS Parsing Memory Corruption Vulnerability

Release Date: 2007-08-15

CVE ID: CVE-2007-0943

http://www.nsfocus.com/english/homepage/research/0701.htm

Affected systems & software

Internet Explorer 5.01

Unaffected systems & software

Summary

NSFocus Security Team discovered a memory corruption vulnerability in IE 5 that allows arbitrary code execution when parsing a malicious CSS file.

Description

There exists a vulnerability when IE 5.0 parses CSS due to insufficient check on the pointer. Out-of-bound pointer reference and memory overwriting might occur in the handling of malformed CSS files, which allows attackers to run arbitrary code via carefully crafted data.

Attackers can run arbitrary code by crafting a malicious WEB page and alluring users to visit it. If the victim is an administrator, then attackers can gain complete control over the system.

The system will be vulnerable even if the security level of IE is set to "High".

Workaround

Do not visit untrusted websites.

Vendor Status

2006.08.31 Informed the vendor 2006.09.01 Vendor confirmed the vulnerability 2007.08.14 Microsoft released MS07-045 to fix the vulnerability.

For more details about Microsoft Security Bulletin, please refer to: http://www.microsoft.com/technet/security/bulletin/MS07-045.mspx

Additional Information

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-0943 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. Candidates may change significantly before they become official CVE entries.

Acknowledgment

Hu Qianwei of NSFocus Security Team found the vulnerability.

DISCLAIMS

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NSFocus Security Team <security@nsfocus.com> NSFOCUS INFORMATION TECHNOLOGY CO.,LTD (http://www.nsfocus.com)