Bug#610792: CVE-2011-0020: heap corruption in libpango

[Moritz Muehlenhoff]

Package: pango1.0
Severity: grave
Tags: security

Discovered by Dan Rosenberg an posted to oss-security:

"When used with FreeType2 as a backend, Pango is vulnerable to heap
corruption when rendering malformed fonts. The vulnerability occurs in
pango_ft2_font_render_box_glyph() in pango/pangoft2-render.c. A buffer
is malloc'd with size box->bitmap.rows * box->bitmap.pitch.
Subsequently, 0xff is written at offsets into this buffer without
checking that these offsets fall within the buffer's boundaries,
leading to heap corruption."

-Dan

[1] https://bugs.launchpad.net/ubuntu/+source/pango1.0/+bug/696616

-- System Information:
Debian Release: 6.0
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.32-5-amd64 (SMP w/2 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash