[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

ZDI-10-152: Apple WebKit RTL LineBox Overflow Remote Code Execution Vulnerability

ZDI-10-152: Apple WebKit RTL LineBox Overflow Remote Code Execution Vulnerability
August 11, 2010

-- CVE ID:

-- CVSS:
10, (AV:N/AC:L/Au:N/C:C/I:C/A:C)

-- Affected Vendors:

-- Affected Products:
Apple WebKit

-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of Apple's Webkit. User interaction is required
to exploit this vulnerability in that the target must visit a malicious
page or open a malicious file.

The specific flaw exists due to the method by which the Webkit library
renders right-to-left text. If a linebox has a width greater than it's
container, Webkit frees an object that upon page destruction is freed
again. An attacker can exploit this to code execute remote code under
the context of the application.

-- Vendor Response:
Apple states:
this issue was fixed in Safari 4.0.5, and iOS 4 for iPhone and iPod
touch iOS 3.2
   iOS 4: http://support.apple.com/kb/HT4225
   Safari 4.0.5: http://support.apple.com/kb/HT4070

-- Disclosure Timeline:
2010-02-18 - Vulnerability reported to vendor
2010-08-11 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by:
    * wushi of team509

-- About the Zero Day Initiative (ZDI):
Established by TippingPoint, The Zero Day Initiative (ZDI) represents 
a best-of-breed model for rewarding security researchers for responsibly
disclosing discovered vulnerabilities.

Researchers interested in getting paid for their security research
through the ZDI can find more information and sign-up at:


The ZDI is unique in how the acquired vulnerability information is
used. TippingPoint does not re-sell the vulnerability details or any
exploit code. Instead, upon notifying the affected product vendor,
TippingPoint provides its customers with zero day protection through
its intrusion prevention technology. Explicit details regarding the
specifics of the vulnerability are not exposed to any parties until
an official vendor patch is publicly available. Furthermore, with the
altruistic aim of helping to secure a broader user base, TippingPoint
provides this vulnerability information confidentially to security
vendors (including competitors) who have a vulnerability protection or
mitigation product.

Our vulnerability disclosure policy is available online at:


Follow the ZDI on Twitter: