CVE-2019-12097
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 · uneditedTelerik Fiddler v5.0.20182.28034 doesn't verify the hash of EnableLoopback.exe before running it, which could lead to code execution or local privilege escalation by replacing the original EnableLoopback.exe.
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 confidenceTelerik Fiddler v5.0.20182.28034 fails to verify the cryptographic hash of EnableLoopback.exe before executing it, allowing an attacker with local filesystem access to replace the legitimate binary with a malicious one. This enables arbitrary code execution or local privilege escalation when Fiddler launches the tampered executable.
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= 5.0.20182.28034CVSS 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
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/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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Check if Fiddler is installedLook for Fiddler installation directory, typically in Program Files or Program Files (x86)\Telerik\Fiddler, or check Windows Registry under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall for Fiddler entryAffected if Fiddler version 5.0.20182.28034 is found installed on the system
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Verify the installed Fiddler versionRight-click on Fiddler.exe, select Properties, go to Details tab and check Product Version, or use command: dir "C:\Program Files (x86)\Fiddler\Fiddler.exe" /vAffected if The installed version matches exactly 5.0.20182.28034
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Locate EnableLoopback.exe in the Fiddler directorySearch for EnableLoopback.exe within the Fiddler installation folder (commonly C:\Program Files (x86)\Fiddler\)Affected if EnableLoopback.exe exists in the Fiddler installation directory and was not found or deleted
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Verify integrity of EnableLoopback.exeCompare the file hash (SHA256 or MD5) of EnableLoopback.exe against the official hash published by Telerik/Progress, or use a file integrity monitoring tool to detect unauthorized modificationsAffected if The file hash differs from the known-good hash or unauthorized modification is detected, indicating possible tampering
A system is affected if Fiddler version 5.0.20182.28034 is installed and EnableLoopback.exe exists in the Fiddler directory without verified integrity checks
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 dataRestrict filesystem write access to the Fiddler installation directory to trusted administrators only, and implement hash verification of EnableLoopback.exe against a known-good hash value before execution.
- Consultation2.0 h
- Implementation6.0 h
- Testing3.0 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 $3,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-12097 — 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-2019-12097 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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