Netty
CVE-2021-21290
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V5 - File Handling Temp file with insecure permissions
|
| Impact | CVSS score of 5.5 (MEDIUM). Attack characteristics: local attack vector, low complexity, low privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | Successful exploitation could compromise the medium-severity affected system. |
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Alert meAnalysisAI
Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 3 packages in maven
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified under CWE-378. Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty before version 4.1.59.Final there is a vulnerability on Unix-like systems involving an insecure temp file. When netty's multipart decoders are used local information disclosure can occur via the local system temporary directory if temporary storing uploads on the disk is enabled. On unix-like systems, the temporary directory is shared between all user. As such, writing to this directory using APIs that do not explicitly set the file/directory permissions can lead to information disclosure. Of note, this does not impact modern MacOS Operating Systems. The method "File.createTempFile" on unix-like systems creates a random file, but, by default will create this file with the permissions "-rw-r--r--". Thus, if sensitive information is written to this file, other local users can read this information. This is the case in netty's "AbstractDiskHttpData" is vulnerable. This has been fixed in version 4.1.59.Final. As a workaround, one may specify your own "java.io.tmpdir" when you start the JVM or use "DefaultHttpDataFactory.setBaseDir(...)" to set the directory to something that is only readable by the current user. Affected products include: Netty, Debian Debian Linux, Quarkus, Oracle Banking Corporate Lending Process Management, Oracle Banking Credit Facilities Process Management. Version information: version 4.1.59..
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Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty before version 4.1.59.Final there is a vulnerability on Unix-like systems involving an insecure temp file. When netty's multipart decoders are used local information disclosure can occur via the local system temporary directory if temporary storing uploads on the disk is enabled. On unix-like systems, the temporary directory is shared between all user. As such, writing to this directory using APIs that do not explicitly set the file/directory permissions can lead to information disclosure. Of note, this does not impact modern MacOS Operating Systems. The method "File.createTempFile" on unix-like systems creates a random file, but, by default will create this file with the permissions "-rw-r--r--". Thus, if sensitive information is written to this file, other local users can read this information. This is the case in netty's "AbstractDiskHttpData" is vulnerable. This has been fixed in version 4.1.59.Final. As a workaround, one may specify your own "java.io.tmpdir" when you start the JVM or use "DefaultHttpDataFactory.setBaseDir(...)" to set the directory to something that is only readable by the current user.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)NVD
Denial of service against HTTP/2 server implementations allows remote unauthenticated attackers to exhaust server resour
Netty before 4.1.42.Final mishandles whitespace before the colon in HTTP headers (such as a "Transfer-Encoding : chunked
Certificate revocation-check bypass in the Netty network framework's OCSP client (io.netty:netty-handler-ssl-ocsp) affec
netty-incubator-codec-ohttp is the OHTTP implementation for netty. Rated critical severity (CVSS 9.1), this vulnerabilit
The netty incubator codec.bhttp is a java language binary http parser. Rated high severity (CVSS 8.1), this vulnerabilit
Netty, an asynchronous, event-driven network application framework, has a vulnerability starting in version 4.1.91.Final
Memory exhaustion in Netty's SctpMessageCompletionHandler (netty-transport-sctp) allows unauthenticated remote peers to
Compression-amplification denial of service in the Netty network framework (versions prior to 4.1.136.Final and 4.2.16.F
Memory-amplification denial of service in the Netty network framework (SPDY/3.1 codec) prior to 4.1.136.Final and 4.2.16
Memory-exhaustion denial of service in Netty's HTTP/3 codec (Http3FrameCodec) affects all releases prior to 4.2.16.Final
Netty's HTTP CORS handler silently rewrites the Vary response header to Vary: Origin in releases before 4.1.137.Final an
Denial of service in the Netty HTTP/3 codec (io.netty:netty-codec-http3) prior to version 4.2.15.Final allows remote una
Exploit-DB