CVE-2021-37148

Name: CVE-2021-37148
Creator: NVD / NIST
Published: 2021-11-03T16:15:08.043+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 2.51%

Last modified Jun 17, 2026

CVE-2021-37148 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Improper input validation vulnerability in header parsing of Apache Traffic Server allows an attacker to smuggle requests. This issue affects Apache Traffic Server 8.0.0 to 8.1.2 and 9.0.0 to 9.0.1.. EPSS estimates a 2.51% chance of exploitation in the next 30 days.

Description

Improper input validation vulnerability in header parsing of Apache Traffic Server allows an attacker to smuggle requests. This issue affects Apache Traffic Server 8.0.0 to 8.1.2 and 9.0.0 to 9.0.1.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

2.51%

82.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apache	Traffic Server	>= 8.0.0, <= 8.1.2
Apache	Traffic Server	>= 9.0.0, <= 9.0.1
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0

References

https://lists.apache.org/thread/k01797hyncx53659wr3o72s5cvkc3164Mailing List, Patch, Vendor Advisory
https://www.debian.org/security/2022/dsa-5153Third Party Advisory
https://lists.apache.org/thread/k01797hyncx53659wr3o72s5cvkc3164Mailing List, Patch, Vendor Advisory
https://www.debian.org/security/2022/dsa-5153Third Party Advisory

Timeline

Published: Nov 3, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-37148?

Improper input validation vulnerability in header parsing of Apache Traffic Server allows an attacker to smuggle requests. This issue affects Apache Traffic Server 8.0.0 to 8.1.2 and 9.0.0 to 9.0.1.

How severe is CVE-2021-37148?

CVE-2021-37148 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 2.51% probability of exploitation in the next 30 days.

How do I fix CVE-2021-37148?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-37148?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST