Fixed
Created: May 25, 2017
Updated: May 29, 2018
Resolved Date: Aug 10, 2017
Found In Version: 9.0.0.6
Fix Version: 9.0.0.8
Severity: Standard
Applicable for: Wind River Linux 9
Component/s: Userspace
A buffer overflow was discovered in libxml2 20904-GITv2.9.4-16-g0741801. The function xmlSnprintfElementContent in valid.c is supposed to recursively dump the element content definition into a char buffer 'buf' of size 'size'. The variable len is assigned strlen(buf). If the content->type is XML_ELEMENT_CONTENT_ELEMENT, then (i) the content->prefix is appended to buf (if it actually fits) whereupon (ii) content->name is written to the buffer. However, the check for whether the content->name actually fits also uses 'len' rather than the updated buffer length strlen(buf). This allows us to write about size many bytes beyond the allocated memory. This vulnerability causes programs that use libxml2, such as PHP, to crash.
https://nvd.nist.gov/vuln/detail/CVE-2017-9047
