Secunia Logo  


Secunia PSI WorldMap
 
PHP "strip_tags()" Function and memory_limit Vulnerabilities
Secunia Advisory: SA12064
Release Date: 2004-07-14
Popularity: 22,604 views

Critical:
Highly critical
Impact: Security Bypass
System access
Where: From remote
Solution Status: Vendor Patch

Software:PHP 4.0.x
PHP 4.1.x
PHP 4.2.x
PHP 4.3.x

Secunia CVSS-2 Score: Available in Secunia business solutions

Subscribe: Instant alerts on relevant vulnerabilities


Advisory Content (Page 1 of 3)[ 1 ] [ 2 ] [ 3 ]

Description:
Stefan Esser has reported two vulnerabilities in PHP, which can be exploited by malicious people to bypass certain security functionality or compromise a vulnerable system.

1) The "strip_tags()" function fails to strip obfuscated HTML tags (e.g. tags with "\0"). This can be exploited to conduct cross-site scripting attacks against sites, which only rely on the "strip_tags()" functionality to prevent such attacks.

NOTE: An HTML tag such as "<script>" with an embedded binary character like "\0" is not a valid HTML entity. However, certain browsers such as Internet Explorer and Safari strip such illegal characters and render it. This is not a vulnerability in those browser, but unfortunate and unnecessary functionality.

2) Various errors within PHP's memory_limit request termination (e.g. when allocating Zend HashTables before proper initialisation) can be exploited to execute arbitrary code by corrupting the heap (e.g. supplying arbitrary HashTable destructor pointers).

Successful exploitation requires that a resource limit has been set via the "memory_limit" configuration directive.

The vulnerabilities have been reported in version 4.3.7 and prior and version 5.0.0RC3 and prior.

Change Page:
[ 1 ] [ 2 ] [ 3 ]



Track this Secunia Advisory
Customers of the Secunia Vulnerability Intelligence solutions will automatically receive updates when new information regarding this advisory is released.

Read more about our Vulnerability Intelligence solutions and what they can do for you and your company.

About this Secunia Advisory
Please note: The information that this Secunia Advisory is based on comes from a third party unless stated otherwise.

Secunia collects, validates, and verifies all vulnerability reports issued by security research groups, vendors, and others.
  
Latest Advisories

Send Feedback to Secunia
If you have new information regarding this Secunia advisory or a product in our database, please send it to us using either our web form or email us at vuln@secunia.com.

Ideas, suggestions, and other feedback are most welcome.

Most Popular - 3 Hours

1. Adobe Illustrator Encapsulated Postscript Parsing Vulnerability // 41 views
2. Kaspersky Anti-Virus 2010 klavemu.kdl Denial of Service Vulnerability // 23 views
3. FreeBSD freebsd-update Insecure Directory Permissions // 20 views
4. Internet Explorer Charset Inheritance Cross-Site Scripting Vulnerability // 17 views
5. Xfig ".fig" File Parsing Buffer Overflow // 16 views
6. Cacti Cross-Site Request Forgery // 15 views
7. transfig ".fig" File Parsing Buffer Overflow // 15 views
8. IBM WebSphere Application Server for z/OS Multiple Vulnerabilities // 14 views
9. Sun Java JDK / JRE Multiple Vulnerabilities // 13 views
10. Sun Products NSS TLS Session Renegotiation Plaintext Injection Vulnerability // 12 views