External risk intelligence

libarchive NULL Pointer Dereference Vulnerability.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2022-36227

libarchive is a library used by various applications to process archive files. While it may be embedded in internet-facing services, the library itself is not a standalone network service or appliance. Exposure depends entirely on the specific host application and whether it processes untrusted user-supplied archives from the internet, making public network-level exposure uncommon for the library in isolation.

Libarchive

3.0.0 to before 3.6.210.0378.2.0 to before 8.2.129.0.0 to before 9.0.69.1.0

Halo Surface Signal: 2 out of 5 — less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory details a flaw in the libarchive software that could potentially lead to system instability or compromise. The issue arises from how the software handles certain file archive operations, specifically when memory allocation fails. While the direct impact is debated, it warrants attention to understand its relevance to our environment.

Software flaw affects archive file processing.
Understand potential for system instability or compromise.
Confirm if this library is used and assess exposure.

Attack Path

How an attacker could exploit the issue

An attacker can reach this vulnerability by submitting a specially crafted archive file to an application that uses a vulnerable version of the libarchive library. If the application processes this archive without properly checking for errors after memory allocation, it can lead to a NULL pointer dereference. While third parties dispute the code-execution impact, in rare circumstances, this could potentially allow an attacker to read or write to memory.

Entry condition: Unauthenticated network access.
Trigger point: Processing a malicious archive file.
Resulting risk: Potential for memory corruption.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability in libarchive could allow an attacker to cause a denial-of-service condition, and in rare circumstances, potentially lead to code execution when processing specially crafted archive files.

Archive processing denial-of-service.
NULL pointer dereference.
Potential for code execution.

Operational Fix

Recommended remediation, mitigation, and detection steps

The libarchive library's handling of potential NULL pointer dereferences when processing archive files introduces risk, particularly if applications rely on it to process external or user-supplied archives. Technical leaders and security teams should coordinate with application owners and infrastructure teams to identify all deployments, assess exposure based on how archives are processed, and prioritize remediation efforts.

Application owners should verify libarchive usage.
Confirm archive processing and exposure first.
Plan remediation based on identified risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Free EASM Trial See How Signal Works

Frequently asked questions

What is libarchive and why do applications use it?

Libarchive is a portable software library designed to read and write a wide variety of archive formats, such as tar, zip, and cpio. Developers integrate it into their own applications to handle compression, decompression, and file extraction tasks. Because it is a foundational component, many different systems—ranging from Linux distributions like Debian and Fedora to enterprise software like Splunk Universal Forwarder—rely on it to manage incoming data streams and file packages.

What does this CVE-2022-36227 vulnerability mean?

This vulnerability is categorized as a NULL pointer dereference, which is a specific weakness class (CWE-476). It occurs when the software fails to verify if a memory allocation operation was successful. If the system runs out of memory and the allocation returns a NULL value, the program may attempt to use that invalid memory address, causing it to crash. In rare, complex scenarios, this flaw might theoretically allow unauthorized access to memory, though the actual security impact is debated.

How can an attacker trigger this bug?

An attacker triggers the vulnerability by providing a specially crafted, malicious archive file to a target application that uses a vulnerable version of libarchive. The flaw is not triggered simply by the presence of the library on a system; it requires the library to actively process the corrupted archive. If the software does not successfully perform a memory allocation and subsequently tries to access the memory location without error handling, the crash or error state occurs.

Is my system at risk according to Halo Surface Signal?

Halo Surface Signal classifies this as unlikely to be directly exposed as a standalone network service. Because libarchive is a library embedded within larger applications, it does not typically listen for connections itself. Your actual risk depends on whether your specific software processes untrusted or user-supplied archives from the internet. If the host application does not accept external archive uploads, the library's exposure to the network remains very limited.

What are the first steps to address this issue?

You should begin by auditing your environment to identify which applications utilize libarchive. Since this is an embedded dependency, you must focus on the software packages—such as Splunk Universal Forwarder—that include the library. Once identified, consult official vendor security bulletins to determine if a patch or update is available for your specific product version. Prioritize updating applications that actively process or extract archive files from untrusted sources.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.