Security readout for executives and security teams
Plain-English summary
This flaw can let an unauthenticated network attacker crash the SAP NetWeaver AS for ABAP RFC Gateway. The known impact is outage, not data theft or data modification. For organizations relying on SAP availability, treat this as a business continuity risk.
Executive priority
High priority for SAP-dependent environments. This is not a confidentiality breach based on the provided sources, but it can disrupt critical business systems without authentication.
Technical view
CVE-2021-27633 affects SAP NetWeaver AS for ABAP RFC Gateway kernel variants listed by SAP. Improper input validation in ThCPIC() lets a specially crafted network packet trigger an internal error and crash the system. CVSS 3.0 is 7.5, with network access, low complexity, no privileges, and high availability impact.
Likely exposure
Exposure is most relevant where SAP NetWeaver AS for ABAP RFC Gateway is reachable over a network, especially from untrusted or broadly accessible segments. The source bundle lists multiple KRNL32NUC, KRNL64NUC, KRNL64UC, and KERNEL version lines as affected.
Exploitation context
The source bundle does not show CISA KEV listing or cite active exploitation. The vulnerability is still operationally serious because it requires no authentication or user interaction and can crash the service.
Researcher notes
Validation should focus on version identification, gateway reachability, and remediation state. Avoid assuming exploit activity or additional impact beyond the source bundle: the stated impact is availability loss only, with no data viewing or modification.
Mitigation direction
- Review SAP Note 3020209 and apply SAP’s current vendor guidance.
- Limit RFC Gateway network access to trusted systems and administrative paths.
- Reduce external or broad internal reachability while remediation is pending.
- Prioritize remediation for production SAP systems supporting critical operations.
Validation and detection
- Inventory SAP NetWeaver AS for ABAP systems and RFC Gateway exposure.
- Compare kernel variants and versions against the affected list in the CVE record.
- Confirm whether SAP Note 3020209 remediation or guidance has been applied.
- Check monitoring for unexpected SAP gateway crashes or availability incidents.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-787: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-27633 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.5HighVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://wiki.scn.sap.com/wiki/pages/viewpage.action?pageId=578125999CVE reference
- https://launchpad.support.sap.com/#/notes/3020209CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.