HOMEVULNERABILITIESCVE-2021-43797
MEDIUM

CVE-2021-43797

CWE-444Published: December 9, 2021· Updated: Jun 17, 2026

6.5
CVSS v3.1

Official Description

Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. Netty prior to version 4.1.71.Final skips control chars when they are present at the beginning / end of the header name. It should instead fail fast as these are not allowed by the spec and could lead to HTTP request smuggling. Failing to do the validation might cause netty to "sanitize" header names before it forward these to another remote system when used as proxy. This remote system can't see the invalid usage anymore, and therefore does not do the validation itself. Users should upgrade to version 4.1.71.Final.

NVD Source

Technical Analysis

CVE-2021-43797 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 6.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Affected Vendors & Products

Debian1 product(s)
debian linux
netapp2 product(s)
oncommand workflow automationsnapcenter
netty1 product(s)
netty
Oracle13 product(s)
banking deposits and lines of credit servicingbanking party managementbanking platformcoherencecommunications cloud native core binding support functioncommunications cloud native core network slice selection functioncommunications cloud native core policycommunications cloud native core security edge protection proxycommunications cloud native core unified data repositorycommunications design studiocommunications instant messaging serverhelidon+1
quarkus1 product(s)
quarkus
Source: NVD CPE · 22 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323
PATCHhttps://www.oracle.com/security-alerts/cpuapr2022.html
PATCHhttps://www.oracle.com/security-alerts/cpujul2022.html
PATCHhttps://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323
PATCHhttps://www.oracle.com/security-alerts/cpuapr2022.html
PATCHhttps://www.oracle.com/security-alerts/cpujul2022.html
ADVISORYhttps://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqq
ADVISORYhttps://lists.debian.org/debian-lts-announce/2023/01/msg00008.html
ADVISORYhttps://security.netapp.com/advisory/ntap-20220107-0003/
ADVISORYhttps://www.debian.org/security/2023/dsa-5316
ADVISORYhttps://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqq
ADVISORYhttps://lists.debian.org/debian-lts-announce/2023/01/msg00008.html
ADVISORYhttps://security.netapp.com/advisory/ntap-20220107-0003/
ADVISORYhttps://www.debian.org/security/2023/dsa-5316

All References (14)

→
https://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323Patch · Third Party Advisory
→
https://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqqThird Party Advisory
→
https://lists.debian.org/debian-lts-announce/2023/01/msg00008.htmlMailing List · Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20220107-0003/Third Party Advisory
→
https://www.debian.org/security/2023/dsa-5316Third Party Advisory
→
https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch · Third Party Advisory
→
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch · Third Party Advisory
→
https://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323Patch · Third Party Advisory
→
https://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqqThird Party Advisory
→
https://lists.debian.org/debian-lts-announce/2023/01/msg00008.htmlMailing List · Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20220107-0003/Third Party Advisory
→
https://www.debian.org/security/2023/dsa-5316Third Party Advisory
→
https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch · Third Party Advisory
→
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch · Third Party Advisory

Quick Facts

CVE IDCVE-2021-43797
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-444
CISA KEVNo
Affected5 vendor(s)
PublishedDec 9, 2021

Related CVEs (CWE-444)

CVE-2025-1867
10.0
CVE-2018-3907
10.0
CVE-2025-55315
9.9
CVE-2024-27922
9.8
CVE-2021-30180
9.8
CVE-2022-2466
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-43797 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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