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SnortApplication

CVE-2007-0251

HIGH · 7.8 CVSS v2.0 Published 2007-01-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
87/100
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
Integer underflow in the DecodeGRE function in src/decode.c in Snort 2.6.1.2 allows remote attackers to trigger dereferencing of certain memory locations via crafted GRE packets, which may cause corruption of log files or writing of sensitive information into log files.

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

Integer underflow vulnerability in Snort 2.6.1.2's DecodeGRE function allows remote attackers to send crafted GRE packets that trigger incorrect memory dereferencing, potentially corrupting log files or causing sensitive information to be written into logs.

MitigationUpgrade Snort to a version that includes the fix for this integer underflow in the GRE packet decoder, or apply the relevant patch to src/decode.c.

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
SnortApplication
Affected:= 2.6.1.2

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
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete

AV:N/AC:L/Au:N/C:N/I:N/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 checks

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

  1. Verify Snort installation version
    Run 'snort -V' or 'snort --version' to display the installed Snort version
    Affected if The displayed version is exactly 2.6.1.2
  2. Locate Snort configuration file
    Check for snort.conf typically in /etc/snort/, /usr/local/etc/snort/, or the directory where Snort was installed
    Affected if A snort.conf file exists and GRE protocol decoding is enabled within it
  3. Confirm GRE decoding is enabled
    Inspect the snort.conf file for 'preprocessor gre' or similar GRE-related configuration directives. Also check runtime command lines for GRE parsing flags
    Affected if GRE preprocessing or decoding is explicitly enabled in configuration or runtime parameters
  4. Check for log anomalies
    Review Snort alert and packet log files for unusual entries, memory corruption indicators, or unexpected writes that may indicate exploitation
    Affected if Logs contain unexpected data patterns, memory addresses, or anomalies consistent with the memory dereferencing described in the CVE

You are affected if Snort version 2.6.1.2 is installed AND GRE packet decoding is enabled in your Snort configuration or runtime settings

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

Upgrade Snort to a version that includes the fix for this integer underflow in the GRE packet decoder, or apply the relevant patch to src/decode.c.

Fix this in Snort Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
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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-2007-0251 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data