CVE-2021-33683

What it is

SAP Web Dispatcher and Internet Communication Manager (ICM), versions - KRNL32NUC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL32UC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL64NUC 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49, KRNL64UC 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49, 7.53, 7.73, WEBDISP 7.53, 7.73, 7.77, 7.81, 7.82, 7.83, KERNEL 7.21, 7.22, 7.49, 7.53, 7.73, 7.77, 7.81, 7.82, 7.83, process invalid HTTP header. The incorrect handling of the invalid Transfer-Encoding header in a particular manner leads to a possibility of HTTP Request Smuggling attack. An attacker could exploit this vulnerability to bypass web application firewall protection, divert sensitive data such as customer requests, session credentials, etc.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. Limited direct impact.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-07-14 12:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:55 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 4.3 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-07-14 12:15 UTC

Last modified

2026-06-17 03:55 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-444

Record status

Modified

Affected

• Sap Web Dispatcher 7.8_kernel_7.21
• Sap Web Dispatcher 7.21ext
• Sap Web Dispatcher 7.22
• Sap Web Dispatcher 7.22ext
• Sap Web Dispatcher 7.49
• Sap Web Dispatcher 7.53
• Sap Web Dispatcher 7.73
• Sap Web Dispatcher 7.77

Attack profile CVSS 3.1 · 4.3

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-33683.md and follow it. Check whether this project is affected by CVE-2021-33683. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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