CVE-2021-4181

HIGH7.5/ 10.0
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Published: December 30, 2021 at 10:15 PM
Modified: November 3, 2025 at 10:15 PM
Source: cve@gitlab.com

Vulnerability Description

Crash in the Sysdig Event dissector in Wireshark 3.6.0 and 3.4.0 to 3.4.10 allows denial of service via packet injection or crafted capture file

CVSS Metrics

Base Score
7.5
Severity
HIGH
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses (CWE)

Source: nvd@nist.gov

AI Security Analysis

01 // Technical Summary

Wireshark, a widely used network protocol analyzer, is vulnerable to a denial-of-service (DoS) attack. A crafted packet or capture file, specifically targeting the Sysdig Event dissector, can trigger a crash, rendering the application unusable. This vulnerability can be exploited by injecting malicious packets into a network or by distributing a compromised capture file.

02 // Vulnerability Mechanism

Step 1: Payload Delivery: An attacker crafts a malicious Sysdig event packet or creates a capture file (.pcap or .pcapng) containing such a packet.

Step 2: Packet Injection/File Opening: The attacker either injects the crafted packet into a network monitored by Wireshark or convinces a user to open the malicious capture file.

Step 3: Dissector Trigger: Wireshark's Sysdig Event dissector attempts to parse the malicious packet.

Step 4: Vulnerability Exploitation: The crafted packet triggers the vulnerability within the Sysdig Event dissector, leading to a crash.

Step 5: Denial of Service: Wireshark crashes, making it unavailable for network analysis until restarted.

03 // Deep Technical Analysis

The vulnerability lies within the Sysdig Event dissector in Wireshark. The dissector, responsible for parsing and interpreting Sysdig event data, contains a flaw that leads to a crash when processing malformed or crafted Sysdig event packets. The root cause is likely related to improper handling of input data, potentially leading to a buffer overflow, integer overflow, or other memory corruption issues within the dissector's parsing logic. The specific function or logic flaw is not explicitly stated in the provided information, but the description points to a problem with how the dissector handles the Sysdig event data, leading to a crash and DoS.

References & Intelligence

https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-4181.json
Source: cve@gitlab.com
Third Party Advisory
https://gitlab.com/wireshark/wireshark/-/merge_requests/5429
Source: cve@gitlab.com
ExploitIssue TrackingThird Party Advisory
https://lists.debian.org/debian-lts-announce/2022/03/msg00041.html
Source: cve@gitlab.com
Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Q6XGBKWSQFCVYUN4ZK3O3NJIFP3OAFVT/
Source: cve@gitlab.com
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/R5AEK3XTOIOGCGUILUFISMGX54YJXWGJ/
Source: cve@gitlab.com
https://security.gentoo.org/glsa/202210-04
Source: cve@gitlab.com
Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html
Source: cve@gitlab.com
Third Party Advisory
https://www.wireshark.org/security/wnpa-sec-2021-21.html
Source: cve@gitlab.com
Vendor Advisory
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-4181.json
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://gitlab.com/wireshark/wireshark/-/merge_requests/5429
Source: af854a3a-2127-422b-91ae-364da2661108
ExploitIssue TrackingThird Party Advisory
https://lists.debian.org/debian-lts-announce/2022/03/msg00041.html
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2024/09/msg00049.html
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Q6XGBKWSQFCVYUN4ZK3O3NJIFP3OAFVT/
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/R5AEK3XTOIOGCGUILUFISMGX54YJXWGJ/
Source: af854a3a-2127-422b-91ae-364da2661108
https://security.gentoo.org/glsa/202210-04
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://www.wireshark.org/security/wnpa-sec-2021-21.html
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory
CVE-2021-4181 - HIGH Severity (7.5) | Free CVE Database | 4nuxd