CVE-2020-25649
Description
A flaw was found in FasterXML Jackson Databind, where it did not have entity expansion secured properly. This flaw allows vulnerability to XML external entity (XXE) attacks. The highest threat from this vulnerability is data integrity.
Statement
Red Hat Enterprise Linux 8 ships a vulnerable version of jackson-databind in the pki-deps:10.6 module. pki-deps:10.6 is for pki-core dependencies, but pki-core does not use the vulnerable DOMDeserializer class and thus has been set to low impact. Future updates may include fixed version of jackson-databind.
Red Hat OpenStack Platform ships OpenDaylight, which contains the vulnerable jackson-databind code. However, OpenDaylight does not expose jackson-databind in a way that would make it vulnerable, lowering the impact of the vulnerability for OpenDaylight. As such, Red Hat will not be providing a fix for OpenDaylight at this time.
Red Hat Virtualization ships a vulnerable version of jackson-databind, however the vulnerable DOMDeserializer class is not used in the code, therefore reducing impact to low.
Red Hat OpenShift Container Platform (OCP) ships a vulnerable version of jackson-databind, but in the affected containers the DOMDeserializer class is not used. Additionally access to the containers is restricted to authenticated users only (OpenShift OAuth authentication) reducing the severity of this vulnerability to Low. In OCP 4 there are no plans to maintain ose-logging-elasticsearch5 container, hence marked as wontfix.
Red Hat Satellite ships affected version of jackson-databind through Candlepin, however, product code does not use DOMDeserializer class and jackson-databind in a vulnerable way. Thus impact has been set to low. A future release may update jackson-databind to a fixed version.
Red Hat Single Sign-On (RH-SSO) ships affected version of jackson-databind, however, none of the product code is using the affected class (DOMDeserializer). Thus impact has been set to low. RH-SSO will consume the fixed artifact from EAP in the next CP.
Mitigation
There is currently no known mitigation for this flaw.
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 | 7.5 | 7.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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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