Security readout for executives and security teams
Plain-English summary
CVE-2021-27634 is a denial-of-service issue in SAP NetWeaver AS for ABAP RFC Gateway. An unauthenticated network attacker can send a specially crafted packet that crashes the system. The sources state data cannot be viewed or changed, but availability can be lost.
Executive priority
Treat this as a high-priority availability risk for SAP environments. It does not indicate data theft or tampering, but an unauthenticated network crash path can disrupt business operations if affected systems are reachable.
Technical view
The vulnerability is improper input validation in method ThCpicDtCreate() affecting listed SAP kernel families for NetWeaver AS for ABAP RFC Gateway. CVSS 3.0 is 7.5, with network attack vector, low complexity, no privileges, no user interaction, and high availability impact only.
Likely exposure
Exposure is most relevant where SAP NetWeaver AS for ABAP RFC Gateway is reachable over a network and runs one of the listed vulnerable kernel versions. The source bundle does not establish internet exposure, deployment prevalence, or exploitability beyond the unauthenticated network crash condition.
Exploitation context
The CVE is not listed as CISA KEV in the supplied data. The provided sources describe unauthenticated network denial of service, but do not cite active exploitation, public exploit use, or attacks in the wild.
Researcher notes
Evidence supports a network-reachable unauthenticated DoS caused by improper input validation in ThCpicDtCreate(). The supplied data names CWE-787, but does not provide exploit details, packet structure, confirmed exploitation, or complete remediation text from SAP Note 3020209.
Mitigation direction
- Review SAP Security Note 3020209 for official remediation guidance.
- Check SAP’s public advisory page for version-specific guidance.
- Inventory affected NetWeaver AS for ABAP RFC Gateway kernel versions.
- If delayed, evaluate vendor-approved network restrictions for RFC Gateway access.
- Plan availability monitoring and recovery until remediation is complete.
Validation and detection
- Identify systems running SAP NetWeaver AS for ABAP RFC Gateway.
- Compare kernel versions against the affected version list.
- Confirm whether SAP Note 3020209 guidance has been applied.
- Validate exposure paths to RFC Gateway from untrusted networks.
- Review outage logs for crashes consistent with RFC Gateway errors.
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
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-27634 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.