CVE-2021-33670Network attack vector

Unauthenticated service crash via unbounded HTTP method tracking

Published Jul 14, 2021 · Updated Aug 3, 2024

Resource exhaustion in SAP NetWeaver AS for Java 7.10 through 7.50 allows remote attackers to crash the Java VM via HTTP. The HTTP Service Monitoring Filter records distinct request methods without bounding the memory used for that tracking, eventually raising OutOfMemoryError. No authentication or user interaction is required; sustained crafted requests interrupt the HTTP service for legitimate users.

CVSS severity7.5
High
EPSS probability3.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in SAP NetWeaver AS for Java 7.10 through 7.50 allows remote attackers to crash the Java VM via HTTP. The HTTP Service Monitoring Filter records distinct request methods without bounding the memory used for that tracking, eventually raising OutOfMemoryError. No authentication or user interaction is required; sustained crafted requests interrupt the HTTP service for legitimate users.

The record

CVE
CVE-2021-33670
Published
Jul 14, 2021
Updated
Aug 3, 2024
Vendor
SAP SE
Product
SAP NetWeaver AS for Java HTTP Provider Service
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 14, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 7.10
  2. Affected versionversion=< 7.11
  3. Affected versionversion=< 7.20
  4. Affected versionversion=< 7.30
  5. Affected versionversion=< 7.31
  6. Affected versionversion=< 7.40
  7. Affected versionversion=< 7.50

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SAP SE · SAP NetWeaver AS for Java HTTP Provider Serviceversion=< 7.10; version=< 7.11; version=< 7.20; version=< 7.30; version=< 7.31; version=< 7.40; version=< 7.50

Published CVSS scores

7.5SAP SECVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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