AccessControl provides a general security framework for use in Zope. Python's "format" functionality allows someone controlling the format string to "read" objects accessible (recursively) via attribute access and subscription from accessible objects. Those attribute accesses and subscriptions use Python's full blown
getitem, not the policy restricted
_getitem_. This can lead to critical information disclosure.
AccessControl already provides a safe variant for
str.format and denies access to
str.format_map is still unsafe. Affected are all users who allow untrusted users to create
AccessControl controlled Python code and execute it. A fix has been introduced in versions 4.4, 5.8 and 6.2. Users are advised to upgrade. There are no known workarounds for this vulnerability.