Debian LinuxOperating system · Debian
CVE-2020-26571
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 · uneditedThe gemsafe GPK smart card software driver in OpenSC before 0.21.0-rc1 has a stack-based buffer overflow in sc_pkcs15emu_gemsafeGPK_init.
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 confidenceStack-based buffer overflow in the sc_pkcs15emu_gemsafeGPK_init function within OpenSC's gemsafe GPK smart card driver. The vulnerability could allow local or adjacent attackers to execute arbitrary code or cause denial of service via crafted smart card data.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Debian LinuxOperating system
= 9.0
FedoraOperating system
= 33<= 0.20.0CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Verify OpenSC is installedRun 'opensc-tool --version' or check your package manager (dpkg -l | grep opensc or rpm -qa | grep opensc)Affected if OpenSC is not installed or the command returns nothing, the vulnerability does not apply. If installed, continue to version check.
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Determine installed OpenSC versionRun 'opensc-tool --version' to see the version number, or query your package manager: 'dpkg -l opensc' (Debian) or 'rpm -q opensc' (Fedora)Affected if Version is 0.20.0 or lower, or the version cannot be determined (likely unpatched). Versions 0.21.0-rc1 and later are not affected.
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Check if gemsafe GPK driver module existsLook for the gemsafe driver file in the OpenSC drivers directory, typically at /usr/lib/opensc/pkcs15-gemsafeGPK.so or /usr/lib64/opensc/pkcs15-gemsafeGPK.soAffected if The driver file exists and OpenSC version is <= 0.20.0, then the vulnerable code path is present.
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Verify pcscd service is active (enables smart card access)Check service status with 'systemctl status pcscd' or 'service pcscd status'Affected if pcscd is running and a Gemsafe GPK card is inserted, the vulnerable function sc_pkcs15emu_gemsafeGPK_init could be triggered via card insertion.
You are affected if OpenSC version 0.20.0 or lower is installed AND the gemsafe GPK driver is present AND a smart card reader with a Gemsafe GPK card could be used in your environment.
Generated from the published advisory. Verify against your own configuration.
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 dataUpdate OpenSC to version 0.21.0-rc1 or later to obtain the patch for this vulnerability.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,464.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-26571 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-26571 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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