A flaw was found in libxml2. This vulnerability occurs when the library processes a specially crafted XML Schema Definition (XSD) validated document that includes an internal entity reference. An attacker could exploit this by providing a malicious document, leading to a type confusion error that causes the application to crash. This results in a denial of service (DoS), making the affected system or application unavailable.
Weakness
The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Libxml2 | Xmlsoft | 2.13.0 (including) | 2.15.3 (excluding) |
| Red Hat Hardened Images | RedHat | libxml2-main-2.15.3-0.1.hum1 | * |
| Libxml2 | Ubuntu | esm-infra/xenial | * |
| Libxml2 | Ubuntu | questing | * |
| Libxml2 | Ubuntu | resolute | * |
Extended Description
When the product accesses the resource using an incompatible type, this could trigger logical errors because the resource does not have expected properties. In languages without memory safety, such as C and C++, type confusion can lead to out-of-bounds memory access. While this weakness is frequently associated with unions when parsing data with many different embedded object types in C, it can be present in any application that can interpret the same variable or memory location in multiple ways. This weakness is not unique to C and C++. For example, errors in PHP applications can be triggered by providing array parameters when scalars are expected, or vice versa. Languages such as Perl, which perform automatic conversion of a variable of one type when it is accessed as if it were another type, can also contain these issues.