CVE-2018-1000844

Description

From CVE.org

Square Open Source Retrofit version Prior to commit 4a693c5aeeef2be6c7ecf80e7b5ec79f6ab59437 contains a XML External Entity (XXE) vulnerability in JAXB that can result in An attacker could use this to remotely read files from the file system or to perform SSRF.. This vulnerability appears to have been fixed in After commit 4a693c5aeeef2be6c7ecf80e7b5ec79f6ab59437.

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 HatNVDcve.org
Base Score6.59.1N/A
Attack VectorNetworkNetworkN/A
Attack ComplexityLowLowN/A
Privileges RequiredNoneNoneN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityLowHighN/A
Integrity ImpactLowHighN/A
Availability ImpactNoneNoneN/A

Vector

Red Hat: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

NVD: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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.

Frequently Asked Questions

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