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Out-of-bounds WriteWeakness · CWE-787

CVE-2025-42940

HIGH · 7.5 CVSS v3.1 Published 2025-11-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
SAP CommonCryptoLib does not perform necessary boundary checks during pre-authentication parsing of manipulated ASN.1 data over the network. This may result in memory corruption followed by an application crash, hence leading to a high impact on availability. There is no impact on confidentiality or integrity.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

SAP CommonCryptoLib lacks proper boundary checks during pre-authentication parsing of ASN.1 data received over the network. Attackers can send manipulated ASN.1 data to trigger memory corruption, causing application crashes and denial of service. This occurs before authentication, making it exploitable against exposed SAP services.

MitigationApply SAP security patches for CommonCryptoLib immediately. Review network exposure of SAP systems and implement filtering for suspicious ASN.1 traffic patterns until patches are deployed.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate SAP CommonCryptoLib installation
    Search for 'libsapcrypto.so' (Unix) or 'sapcrypto.dll' (Windows) in typical SAP installation directories such as /sapmnt/<SID>/sybase/lib, /usr/sap/<SID>/SYS/exe/run, or the SAP installation root. Use file system search commands like 'find / -name libsapcrypto* 2>/dev/null' on Unix or Check SAP Note 1848999 for official library locations.
    Affected if The CommonCryptoLib library file cannot be found on the system (not affected or not installed)
  2. Determine installed CommonCryptoLib version
    Run 'sapgenpse -v' or 'sapcrypto version' if available, or check the file version metadata of the sapcrypto DLL/SO using 'file' command on Unix or right-click Properties on Windows. Consult SAP Note 1848999 for version retrieval methods specific to your SAP release.
    Affected if Version cannot be determined or is lower than the version addressed in SAP security patches for CVE-2025-42940
  3. Identify SAP services using CommonCryptoLib
    Review SAP system profile parameters (transaction RZ11) for parameters like 'ssl/ssl_lib' and check which SAP processes are running (transaction SM37). CommonCryptoLib is used by SAP Web Dispatcher, SAP Gateway, SAP Message Server, and SAP Start Service.
    Affected if No SAP processes using CommonCryptoLib are running (the vulnerability only applies to active services)
  4. Assess network exposure of vulnerable SAP services
    Check SAP Web Dispatcher and Gateway exposure using transaction SMICM (Internet Communication Manager). Review firewall rules and network ACLs governing access to SAP ports (32<instance>, 5<system number>13, 80xx, 443xx). Use 'netstat -an | grep -E "(32|5|80|443)"' to list listening SAP ports.
    Affected if SAP services using CommonCryptoLib are accessible from untrusted networks (the flaw is exploitable pre-authentication over the network)
  5. Review logs for ASN.1 parsing failures
    Examine SAP dev traces in /usr/sap/<SID>/D<instance>/work/ and transaction SLG1 (Application Log) for entries containing 'ASN.1', 'parse error', 'memory', 'crash', or 'abap runtime error' around the time of any service interruptions.
    Affected if Logs show repeated ASN.1 parsing errors, memory corruption indicators, or unexplained service crashes

User is affected if SAP CommonCryptoLib is installed and running with an unpatched version, and SAP services using it are network-accessible, enabling pre-authentication ASN.1 exploits.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply SAP security patches for CommonCryptoLib immediately. Review network exposure of SAP systems and implement filtering for suspicious ASN.1 traffic patterns until patches are deployed.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA4.0 h
40.0 hours of engineering $7,000
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-42940 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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