CVE-2020-24616
Description
A flaw was found in FasterXML jackson-databind 2.x in versions prior to 2.9.10.6. The interaction between serialization gadgets and typing are mishandled. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Statement
The Red Hat JBoss Enterprise Application Platform 7 does ship the vulnerable component but has a mandatory whitelist which blocks all wicked serializing classes and does not enable the unsafe conditions needed to exploit.
While OpenShift Container Platform's elasticsearch plugins do ship the vulnerable component, it doesn't do any of the unsafe things described in https://access.redhat.com/solutions/3279231. We may update the jackson-databind dependency in a future release.
The PKI module as shipped in Red Hat Enterprise Linux 8 and Red Hat Satellite 6 does not enable polymorphic deserialization which is a required configuration for the vulnerability to be used, lowering the impact of the vulnerability for the Product. We may update the jackson-databind dependency in a future release.
Red Hat OpenStack Platform ships OpenDaylight, which contains the vulnerable jackson-databind. 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 Satellite 6.6 and later ship Candlepin with an already fixed version of jackson-databind.
Mitigation
The following conditions are needed for an exploit, we recommend avoiding all if possible:
* Deserialization from sources you do not control
* `enableDefaultTyping()`
* `@JsonTypeInfo using `id.CLASS` or `id.MINIMAL_CLASS`
* avoid br.com.anteros.dbcp in the classpath
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.1 | 8.1 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
The AC should be High because there are sufficient factors beyond the attacker's control:
- Accepts JSON content sent by an untrusted client
- Has the “gadget” class br.com.anteros.dbcp.AnterosDBCPDataSource in the Java classpath: and specifically, the class works with Jackson
- Enable polymorphic type handling: objectMapper.enableDefaultTyping();
- Use a version of Jackson that does not (yet) block “gadget” class br.com.anteros.dbcp.AnterosDBCPDataSource The vulnerability can be exploited only if all of these conditions are true. [1] This set of conditions, we feel reflects AC:H rather than AC:L. [1] https://medium.com/@cowtowncoder/on-jackson-cves-dont-panic-here-is-what-you-need-to-know-54cd0d6e8062
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Files or Directories; Read Application Data
The injected code could access restricted data / files.
Access Control
Technical Impact: Bypass Protection Mechanism
In some cases, injectable code controls authentication; this may lead to a remote vulnerability.
Access Control
Technical Impact: Gain Privileges or Assume Identity
Injected code can access resources that the attacker is directly prevented from accessing.
Integrity,Confidentiality,Availability,Other
Technical Impact: Execute Unauthorized Code or Commands
Code injection attacks can lead to loss of data integrity in nearly all cases as the control-plane data injected is always incidental to data recall or writing. Additionally, code injection can often result in the execution of arbitrary code.
Non-Repudiation
Technical Impact: Hide Activities
Often the actions performed by injected control code are unlogged.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
