CVE-2021-27633Network attack vector

Unauthenticated service crash via malformed RFC packet

Published Jun 9, 2021 · Updated Aug 3, 2024

Memory corruption in the RFC Gateway of SAP NetWeaver Application Server for ABAP allows remote attackers to crash the system with a crafted RFC packet. ThrtHdlAppc modifies attacker-controlled packet data and passes it through ThSAPCMSEND to the disp+work binary, where ThCPIC performs an out-of-bounds write and terminates the system. The RFC Gateway is reachable over the network without authentication; exploitation interrupts service but does not expose or modify system data.

CVSS severity7.5
High
EPSS probability1.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in the RFC Gateway of SAP NetWeaver Application Server for ABAP allows remote attackers to crash the system with a crafted RFC packet. ThrtHdlAppc modifies attacker-controlled packet data and passes it through ThSAPCMSEND to the disp+work binary, where ThCPIC performs an out-of-bounds write and terminates the system. The RFC Gateway is reachable over the network without authentication; exploitation interrupts service but does not expose or modify system data.

The record

CVE
CVE-2021-27633
Published
Jun 9, 2021
Updated
Aug 3, 2024
Vendor
SAP SE
Product
SAP NetWeaver Application Server for ABAP
Classifications
CWE-787, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 9, 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=< 7.22
  2. Affected versionversion=< 7.22EXT
  3. Affected versionversion=< 7.49
  4. Affected versionversion=< 7.53
  5. Affected versionversion=< 7.73
  6. Affected versionversion=< 7.77
  7. Affected versionversion=< 7.81
  8. Affected versionversion=< 7.82
  9. Affected versionversion=< 7.83
  10. Affected versionversion=< 8.04
  11. Affected versionversion=< KERNEL - 7.22
  12. Affected versionversion=< KRNL32NUC - 7.22
  13. Affected versionversion=< KRNL64NUC - 7.22
  14. Affected versionversion=< KRNL64UC - 8.04

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SAP SE · SAP NetWeaver Application Server for ABAPversion=< 7.22; version=< 7.22EXT; version=< 7.49; version=< 7.53; version=< 7.73; version=< 7.77; version=< 7.81; version=< 7.82; version=< 7.83; version=< 8.04; version=< KERNEL - 7.22; version=< KRNL32NUC - 7.22; version=< KRNL64NUC - 7.22; version=< KRNL64UC - 8.04

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-787Out-of-bounds Write
T1499Endpoint Denial of Service

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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