What is CVE-2020-18976?

CVE-2020-18976 is a medium-severity vulnerability in Broadcom Tcpreplay, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 5.5/10. Published 2021-08-25.

How severe is CVE-2020-18976?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in Broadcom Tcpreplay

CVE-2020-18976

Buffer Overflow in Tcpreplay v4.3.2 allows attackers to cause a Denial of Service via the 'do_checksum' function in 'checksum.c'. It can be triggered by sending a crafted pcap file to the 'tcpreplay-edit' binary. This issue is different than CVE-2019-8381.

Vulnerability class: Buffer Overflow

Published 2021-08-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (49.8th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: +0.000

Affected products

Broadcom Tcpreplay — versions 4.3.2

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

github.com/appneta/tcpreplay/issues/556 (Exploit, Patch, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2020-18976?: CVE-2020-18976 is a medium-severity vulnerability in Broadcom Tcpreplay, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 5.5/10. Published 2021-08-25.
How severe is CVE-2020-18976?: Medium severity. CVSS v3 base score is 5.5 out of 10.