CVE-2019-14540
Description
A flaw was discovered in FasterXML jackson-databind, where it would permit polymorphic deserialization of malicious objects using the HikariConfig gadget when used in conjunction with polymorphic type handling methods such as enableDefaultTyping() or when @JsonTypeInfo is using Id.CLASS or Id.MINIMAL_CLASS or in any other way which ObjectMapper.readValue might instantiate objects from unsafe sources. An attacker could use this flaw to execute arbitrary code.
Statement
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.
Satellite 6 does not enable polymorphic unmarshmalling, which is a required configuration for the vulnerability to be used. We may update the jackson-databind dependency in a future release.
Mitigation
This vulnerability relies on com.zaxxer.hikari.HikariConfig being present in the application's ClassPath. Hikari is not packaged as an RPM for Red Hat Enterprise Linux or Red Hat Software Collections. Applications using jackson-databind that do not also use com.zaxxer.hikari are not impacted by this vulnerability.
A mitigation to this class of problem in jackson-databind is to not trigger polymorphic desrialization globally by using: objectMapper.enableDefaultTyping() and rather use @JsonTypeInfo on the class property to explicitly define the type information. For more information on this issue please refer to https://www.github.com/mbechler/marshalsec/blob/master/marshalsec.pdf?raw=true
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 | 9.8 | 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 | High | High | N/A |
| Integrity Impact | None | High | N/A |
| Availability Impact | None | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD: CVSS:3.1/AV:N/AC:L/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.
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