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Security Bulletin: Vulnerabilities in Netty-codec and Netty-handler might affect IBM Storage Defender Copy Data Management

Security Bulletin


Summary

IBM Storage Defender Copy Data Management can be affected by vulnerabilities in Netty-codec and Netty-handler. Vulnerabilities include an incorrect validation of special crafted packet via SslHandler can lead to a native crash, the `SniHandler` can allocate up to 16MB of heap for each channel during the TLS handshake which is possible to craft a packet that makes the `SslClientHelloHandler`, allows remote attackers to cause a denial of service (infinite loop), a vulnerability on Unix-like systems involving an insecure temp file, the malicious input can trigger an OOME and so a DoS attack, the Snappy frame decoder function doesn't restrict the chunk length which may lead to excessive memory usage, the HTTP/2 protocol allows a denial of service and vulnerable to a man-in-the-middle attack caused by improper hostname verification as described by the CVEs in the "Vulnerability Details" section.

Vulnerability Details

CVEID:   CVE-2025-24970
DESCRIPTION:   Netty, an asynchronous, event-driven network application framework, has a vulnerability starting in version 4.1.91.Final and prior to version 4.1.118.Final. When a special crafted packet is received via SslHandler it doesn't correctly handle validation of such a packet in all cases which can lead to a native crash. Version 4.1.118.Final contains a patch. As workaround its possible to either disable the usage of the native SSLEngine or change the code manually.
CWE:   CWE-20: Improper Input Validation
CVSS Source:   security-advisories@github.com
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:   CVE-2023-34462
DESCRIPTION:   Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. The `SniHandler` can allocate up to 16MB of heap for each channel during the TLS handshake. When the handler or the channel does not have an idle timeout, it can be used to make a TCP server using the `SniHandler` to allocate 16MB of heap. The `SniHandler` class is a handler that waits for the TLS handshake to configure a `SslHandler` according to the indicated server name by the `ClientHello` record. For this matter it allocates a `ByteBuf` using the value defined in the `ClientHello` record. Normally the value of the packet should be smaller than the handshake packet but there are not checks done here and the way the code is written, it is possible to craft a packet that makes the `SslClientHelloHandler`. This vulnerability has been fixed in version 4.1.94.Final.
CWE:   CWE-400: Uncontrolled Resource Consumption
CVSS Source:   IBM X-Force
CVSS Base score:   6.5
CVSS Vector:   (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)

CVEID:   CVE-2016-4970
DESCRIPTION:   handler/ssl/OpenSslEngine.java in Netty 4.0.x before 4.0.37.Final and 4.1.x before 4.1.1.Final allows remote attackers to cause a denial of service (infinite loop).
CWE:   CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')
CVSS Source:   IBM X-Force
CVSS Base score:   5.3
CVSS Vector:   (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)

CVEID:   CVE-2021-21290
DESCRIPTION:   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.
CWE:   CWE-378: Creation of Temporary File With Insecure Permissions
CVSS Source:   IBM X-Force
CVSS Base score:   3.3
CVSS Vector:   (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N)

CVEID:   CVE-2021-37136
DESCRIPTION:   The Bzip2 decompression decoder function doesn't allow setting size restrictions on the decompressed output data (which affects the allocation size used during decompression). All users of Bzip2Decoder are affected. The malicious input can trigger an OOME and so a DoS attack
CWE:   CWE-400: Uncontrolled Resource Consumption
CVSS Source:   IBM X-Force
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:   CVE-2021-37137
DESCRIPTION:   The Snappy frame decoder function doesn't restrict the chunk length which may lead to excessive memory usage. Beside this it also may buffer reserved skippable chunks until the whole chunk was received which may lead to excessive memory usage as well. This vulnerability can be triggered by supplying malicious input that decompresses to a very big size (via a network stream or a file) or by sending a huge skippable chunk.
CWE:   CWE-400: Uncontrolled Resource Consumption
CVSS Source:   IBM X-Force
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:   CVE-2023-44487
DESCRIPTION:   The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.
CWE:   CWE-400: Uncontrolled Resource Consumption
CVSS Source:   IBM X-Force
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

IBM X-Force ID:   221368
DESCRIPTION:   Netty is vulnerable to a man-in-the-middle attack, caused by improper hostname verification. An attacker could exploit this vulnerability to launch a man-in-the-middle attack and gain access to the communication channel between endpoints to obtain sensitive information or further compromise the system.
CWE:   CWE-300: Channel Accessible by Non-Endpoint
CVSS Source:   IBM X-Force
CVSS Base score:   7.4
CVSS Vector:   (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N)

Affected Products and Versions

Affected Product(s)Version(s)
IBM Storage Copy Data Management2.2.0.0 - 2.2.26.0

Remediation/Fixes

Affected Versions Fixing LevelPlatformLink to Fix and Instructions
2.2.0.0 - 2.2.26.02.2.27.0Linux 

Workarounds and Mitigations

None

Get Notified about Future Security Bulletins

References

Off

Acknowledgement

Change History

26 Sep 2025: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.

Document Location

Worldwide

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Document Information

Modified date:
26 September 2025

UID

ibm17244580