CVE-2011-5123
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 Antivirus component in Comodo Internet Security before 5.3.175888.1227 does not check whether X.509 certificates in signed executable files have been revoked, which has unknown impact and remote attack vectors.
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 · moderate confidenceThe Comodo Internet Security antivirus component fails to perform X.509 certificate revocation checks on signed executable files before version 5.3.175888.1227. This means the software validates that a file is digitally signed but does not verify whether the signing certificate has been revoked, allowing potentially malicious executables with revoked or compromised certificates to pass validation.
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<= 5.3.174622.1216= 3.0.14.276= 3.0.15.277= 3.0.16.295= 3.0.17.304= 3.0.18.309= 3.0.19.318= 3.0.20.320= 3.0.22.349= 3.0.23.364= 3.0.24.368= 3.0.25.378CVSS 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
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:N/AC:L/Au:N/C:C/I:C/A:C
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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Locate Comodo Internet Security installationCheck the Windows registry under HKLM\Software\Comodo\ or look in Program Files for Comodo folder. Common paths: C:\Program Files\Comodo\ or C:\Program Files (x86)\Comodo\Affected if The software is not found in expected locations or registry keys are missing
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Find the installed version numberRight-click the main executable (typically cmd.exe or Comodo Internet Security.exe) in the installation folder, select Properties, then check the Details tab for Product Version. Alternatively, use command: reg query "HKLM\Software\Comodo" /v VersionAffected if The version displayed cannot be read or the registry query returns no version value
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Compare version to affected rangesCompare your installed version number to: 5.3.174622.1216 (any version at or below this) OR any of these: 3.0.14.276, 3.0.15.277, 3.0.16.295, 3.0.17.304, 3.0.18.309, 3.0.19.318, 3.0.20.320, 3.0.22.349, 3.0.23.364, 3.0.24.368, 3.0.25.378Affected if Your installed version matches one of these affected version numbers or is lower than 5.3.174622.1216
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Confirm the certificate validation behaviorTest by attempting to run a test executable signed with a known revoked certificate (in a safe test environment). Monitor Comodo's response - it should block the file if revocation checking is working, or allow it if the vulnerability exists.Affected if Comodo allows execution of files with revoked certificates without warning or block
You are affected if Comodo Internet Security is installed with version 5.3.174622.1216 or lower, or any of the specific 3.0.x versions listed, and the software does not verify certificate revocation status for signed executables.
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.
dbcve · scopedUpgrade Comodo Internet Security to version 5.3.175888.1227 or later, which implements proper X.509 certificate revocation checking (CRL/OCSP) for signed executables.
Comodo Internet Security 5.3.175888.1227 or later (or latest 5.x release)
- 1. Open Comodo Internet Security application
- 2. Navigate to the 'Settings' or 'General Settings' section
- 3. Look for 'Check for updates' or 'Update' option
- 4. Alternatively, download the latest version from Comodo's official website at comodo.com
- 5. Ensure the updated version is 5.3.175888.1227 or later
- 6. After update, verify the Antivirus component now checks certificate revocation status
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation40.0 h
- Testing16.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $18,944.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-5123 — 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-2011-5123 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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- 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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