CVE-2018-5968
Description
A deserialization flaw was discovered in the jackson-databind that could allow an unauthenticated user to perform code execution by sending the maliciously crafted input to the readValue method of the ObjectMapper. This issue extends the previous flaws CVE-2017-7525 and CVE-2017-17485 by blacklisting more classes that could be used maliciously.
Statement
JBoss EAP 7.x only uses the vulnerable Jackson Databind library for marshalling and unmarshalling of JSON objects passed to JAX-RS webservices. Some advice about how to remain safe when using JAX-RS webservices on JBoss EAP 7.x is available here:
https://access.redhat.com/solutions/3279231
This issue affects the versions of jackson-databind (in Satellite 6.0 and 6.1) and candlepin (which embeds a copy of jackson-databind in Satellite 6.2) as shipped with Red Hat Satellitw 6.x. However the affected code is NOT used at this time:
Candlepin currently uses the default type resolution configuration for the ObjectMappers it creates/uses. Nowhere in candlepin do we enable global polymorphic deserialization via enableDefaultTyping(...), therefore based on the documentation sited BZ 1462702 , candlepin should not be affected.
However as the vulnerable software ships with the product we have marked them as vulnerable to ensure the issue is tracked.
Red Hat Subscription Asset Manager version 1 is now in a reduced support phase receiving only Critical impact security fixes. This issue has been rated as having Important security impact and is not currently planned to be addressed in future updates.
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 | 8.1 | 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:3.0/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
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Application Data; Unexpected State
Attackers can modify unexpected objects or data that was assumed to be safe from modification. Deserialized data or code could be modified without using the provided accessor functions, or unexpected functions could be invoked.
Availability
Technical Impact: DoS: Resource Consumption (CPU)
If a function is making an assumption on when to terminate, based on a sentry in a string, it could easily never terminate.
Other
Technical Impact: Varies by Context
The consequences can vary widely, because it depends on which objects or methods are being deserialized, and how they are used. Making an assumption that the code in the deserialized object is valid is dangerous and can enable exploitation. One example is attackers using gadget chains to perform unauthorized actions, such as generating a shell.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
