CVE-2022-46751
Description
From CVE.org
Improper Restriction of XML External Entity Reference, XML Injection (aka Blind XPath Injection) vulnerability in Apache Software Foundation Apache Ivy.This issue affects any version of Apache Ivy prior to 2.5.2. When Apache Ivy prior to 2.5.2 parses XML files - either its own configuration, Ivy files or Apache Maven POMs - it will allow downloading external document type definitions and expand any entity references contained therein when used. This can be used to exfiltrate data, access resources only the machine running Ivy has access to or disturb the execution of Ivy in different ways. Starting with Ivy 2.5.2 DTD processing is disabled by default except when parsing Maven POMs where the default is to allow DTD processing but only to include a DTD snippet shipping with Ivy that is needed to deal with existing Maven POMs that are not valid XML files but are nevertheless accepted by Maven. Access can be be made more lenient via newly introduced system properties where needed. Users of Ivy prior to version 2.5.2 can use Java system properties to restrict processing of external DTDs, see the section about "JAXP Properties for External Access restrictions" inside Oracle's "Java API for XML Processing (JAXP) Security Guide".
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.2 | 8.2 | 8.2 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | None | None | None |
| Availability Impact | Low | Low | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
If the attacker is able to include a crafted DTD and a default entity resolver is enabled, the attacker may be able to access arbitrary files on the system. By submitting an XML file that defines an external entity with a file:// URI, an attacker can cause the processing application to read the contents of a local file. For example, a URI such as "file:///c:/winnt/win.ini" designates (in Windows) the file C:\Winnt\win.ini, or file:///etc/passwd designates the password file in Unix-based systems. Once the content of the URI is read, it is fed back into the application that is processing the XML. This application may echo back the data (e.g., in an error message), thereby exposing the file contents.
Integrity
Technical Impact: Bypass Protection Mechanism
An attacker may supply a crafted DTD using URIs with schemes such as http://, forcing the application to make outgoing HTTP requests to servers that the attacker cannot reach directly, which can be used to bypass firewall restrictions; hide the source of attacks such as port scanning; or otherwise leverage the server's trust relationship with other entities.
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
The product could consume excessive CPU cycles or memory using a URI that points to a large file, or a device that always returns data such as /dev/random. Alternately, the URI could reference a file that contains many nested or recursive entity references to further slow down parsing.
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