CVE-2021-33677Public exploitNetwork attack vector

User enumeration via distinct RFC error responses

Published Jul 14, 2021 · Updated Aug 3, 2024

Information disclosure in SAP NetWeaver AS ABAP 700, 702, 730, 731, 740, 750, 784, and 804 allows remote attackers to enumerate users. BGRFC_PREPARE_EXT_DEBUGGING passes an attacker-controlled RFC_USERNAME to SUSR_CHECK_DEBUG_ABILITY, which queries USR02 and returns distinct errors for nonexistent, locked, or unauthorized accounts. Direct use requires a low-context RFC user, while unauthenticated reachability depends on chaining a separate user-context flaw.

CVSS severity6.5
Medium
EPSS probability0.94%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in SAP NetWeaver AS ABAP 700, 702, 730, 731, 740, 750, 784, and 804 allows remote attackers to enumerate users. BGRFC_PREPARE_EXT_DEBUGGING passes an attacker-controlled RFC_USERNAME to SUSR_CHECK_DEBUG_ABILITY, which queries USR02 and returns distinct errors for nonexistent, locked, or unauthorized accounts. Direct use requires a low-context RFC user, while unauthenticated reachability depends on chaining a separate user-context flaw.

The record

CVE
CVE-2021-33677
Published
Jul 14, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1087
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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
6.5SAP SECVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

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 exploitPublished

Weakness, pattern, technique

T1087Account Discovery

Public exploit references

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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