Asterisk is an open source private branch exchange and telephony toolkit. Prior to versions 20.7-cert9, 20.18.2, 21.12.1, 22.8.2, and 23.2.2, the ast_xml_open() function in xml.c parses XML documents using libxml with unsafe parsing options that enable entity expansion and XInclude processing. Specifically, it invokes xmlReadFile() with the XML_PARSE_NOENT flag and later processes XIncludes via xmlXIncludeProcess().If any untrusted or user-supplied XML file is passed to this function, it can allow an attacker to trigger XML External Entity (XXE) or XInclude-based local file disclosure, potentially exposing sensitive files from the host system. This can also be triggered in other cases in which the user is able to supply input in xml format that triggers the asterisk process to parse it. This issue has been patched in versions 20.7-cert9, 20.18.2, 21.12.1, 22.8.2, and 23.2.2.
Weakness
The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Asterisk | Sangoma | * | 20.18.2 (excluding) |
| Asterisk | Sangoma | 21.0.0 (including) | 21.12.1 (excluding) |
| Asterisk | Sangoma | 22.0.0 (including) | 22.8.2 (excluding) |
| Asterisk | Sangoma | 23.0.0 (including) | 23.2.2 (excluding) |
| Certified_asterisk | Sangoma | * | 18.9 (including) |
| Certified_asterisk | Sangoma | 20.7-cert1 (including) | 20.7-cert1 (including) |
| Certified_asterisk | Sangoma | 20.7-cert1-rc1 (including) | 20.7-cert1-rc1 (including) |
| Certified_asterisk | Sangoma | 20.7-cert1-rc2 (including) | 20.7-cert1-rc2 (including) |
| Certified_asterisk | Sangoma | 20.7-cert2 (including) | 20.7-cert2 (including) |
| Certified_asterisk | Sangoma | 20.7-cert3 (including) | 20.7-cert3 (including) |
| Certified_asterisk | Sangoma | 20.7-cert4 (including) | 20.7-cert4 (including) |
| Certified_asterisk | Sangoma | 20.7-cert5 (including) | 20.7-cert5 (including) |
| Certified_asterisk | Sangoma | 20.7-cert6 (including) | 20.7-cert6 (including) |
| Certified_asterisk | Sangoma | 20.7-cert7 (including) | 20.7-cert7 (including) |
| Certified_asterisk | Sangoma | 20.7-cert8 (including) | 20.7-cert8 (including) |