CVE-2021-45387Public exploit

Process crash via misparsed IPv4 packet offset

Published Feb 11, 2022 · Updated Aug 4, 2024

Reachable assertion in tcpprep in tcpreplay 4.3.4 allows local users to crash the process by supplying a crafted PCAP file. The IPv4 tree builder reads the packet header at a fixed Ethernet offset instead of the parsed link-layer length, producing an address that fails the ip == newnode->u.ip assertion in add_tree_ipv4(). Exploitation requires a user to run tcpprep against attacker-controlled capture data; the resulting SIGABRT terminates that tcpprep process.

CVSS severity5.5
Medium
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in tcpprep in tcpreplay 4.3.4 allows local users to crash the process by supplying a crafted PCAP file. The IPv4 tree builder reads the packet header at a fixed Ethernet offset instead of the parsed link-layer length, producing an address that fails the ip == newnode->u.ip assertion in add_tree_ipv4(). Exploitation requires a user to run tcpprep against attacker-controlled capture data; the resulting SIGABRT terminates that tcpprep process.

The record

CVE
CVE-2021-45387
Published
Feb 11, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-617, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 11, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

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

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-617Reachable Assertion
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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