CVE-2019-17571
Description
A flaw was discovered in Log4j, where a vulnerable SocketServer class may lead to the deserialization of untrusted data. This flaw allows an attacker to remotely execute arbitrary code when combined with a deserialization gadget.
Statement
This is the same issue as CVE-2017-5645. MITRE has CVE-2017-5645 to a similar flaw found in log4j-2.x. The flaw found in log4j-1.2 has been assigned CVE-2019-17571. CVE-2019-17571 has been addressed in Red Hat Enterprise Linux via RHSA-2017:2423. Also the rh-java-common-log4j package shipped with Red Hat Software Collections was addressed via RHSA-2017:1417
In Satellite 5.8, although the version of log4j as shipped in the nutch package is affected, nutch does not load any of the SocketServer classes from log4j. Satellite 5 is considered not vulnerable to this flaw since the affected code can not be reached.
Mitigation
Please note that the Log4j upstream strongly recommends against using the SerializedLayout with the SocketAppenders. Customers may mitigate this issue by removing the SocketServer class outright; or if they must continue to use SocketAppenders, they can modify their SocketAppender configuration from SerializedLayout to use JsonLayout instead. An example of this in log4j-server.properties might look like this:
log4j.appender.file.layout=org.apache.log4j.JsonLayout
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 | 9.8 | 9.8 | 9.8 |
| 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 | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: 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.
Frequently Asked Questions
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