CVE-2021-41043Public exploit

Process crash via freed pcap handle reuse

Published Jan 5, 2022 · Updated Aug 4, 2024

Use-after-free in tcpslice before 1.5 allows context-dependent attackers to crash the process through a crafted packet-capture file. In extract_slice(), the input-filtering loop can close the first pcap handle before pcap_dump_open() reuses that freed handle to obtain the output link-layer type. A user must invoke output writing on a crafted capture whose first input fails the slice condition; only a process crash is confirmed.

CVSS severity5.5
Medium
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in tcpslice before 1.5 allows context-dependent attackers to crash the process through a crafted packet-capture file. In extract_slice(), the input-filtering loop can close the first pcap handle before pcap_dump_open() reuses that freed handle to obtain the output link-layer type. A user must invoke output writing on a crafted capture whose first input fails the slice condition; only a process crash is confirmed.

The record

CVE
CVE-2021-41043
Published
Jan 5, 2022
Updated
Aug 4, 2024
Vendor
The Tcpdump Group
Product
tcpslice
Classifications
CWE-416, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 5, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <1.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Tcpdump Group · tcpsliceversion=unspecified <1.5

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1204.002User Execution: Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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