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Debian LinuxOperating system · Debian

CVE-2014-6272

HIGH · 7.5 CVSS v2.0 Published 2015-08-24
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
Multiple integer overflows in the evbuffer API in Libevent 1.4.x before 1.4.15, 2.0.x before 2.0.22, and 2.1.x before 2.1.5-beta allow context-dependent attackers to cause a denial of service or possibly have other unspecified impact via "insanely large inputs" to the (1) evbuffer_add, (2) evbuffer_expand, or (3) bufferevent_write function, which triggers a heap-based buffer overflow or an infinite loop. NOTE: this identifier has been SPLIT per ADT3 due to different affected versions. See CVE-2015-6525 for the functions that are only affected in 2.0 and later.

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 overflow vulnerabilities in Libevent's evbuffer API (evbuffer_add, evbuffer_expand, bufferevent_write functions) allow attackers to trigger heap-based buffer overflows or infinite loops by providing excessively large inputs, potentially leading to denial of service or remote code execution.

MitigationUpgrade Libevent to version 1.4.15+, 2.0.22+, or 2.1.5-beta or later to patch the integer overflow vulnerabilities in the evbuffer functions.

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
Affected:= 7.0
LibeventApplication
Affected:= 1.4.0= 1.4.1= 1.4.2= 1.4.3= 1.4.4= 1.4.5= 1.4.6= 1.4.7= 1.4.8= 1.4.9= 1.4.10= 1.4.11

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
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:L/Au:N/C:P/I:P/A:P

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. Identify installed Libevent version
    Run `pkg-config --modversion libevent` or check the library file: `ls -la /usr/lib/libevent*` and examine the package manager: `dpkg -l | grep libevent` (Debian) or `rpm -qa | grep libevent` (RHEL). Alternatively, check the soname: `ldd <executable> | grep libevent` and then `objdump -p /usr/lib/libevent.so.0 2>/dev/null | grep VERSION`
    Affected if The version is 1.4.0 through 1.4.11 (or Debian 7.0 with bundled Libevent 1.4.x)
  2. Find executables using Libevent
    Search for binaries or libraries that link against Libevent: `ldconfig -p | grep libevent` or use `nm`/`objdump` on suspected binaries to find references to evbuffer_add, evbuffer_expand, or bufferevent_write symbols
    Affected if Applications dynamically link to a vulnerable Libevent library version
  3. Inspect application code for vulnerable function usage
    If you have access to the source code, search for calls to evbuffer_add(), evbuffer_expand(), or bufferevent_write() and trace whether the length parameter (nbytes/datlen) can be controlled by untrusted input
    Affected if The code passes user-controlled large size values to these functions without proper validation
  4. Check input validation for evbuffer operations
    Review application logic around buffer operations: verify if there are size checks or limits on input lengths before calling evbuffer_add or bufferevent_write. Look for patterns like `evbuffer_add(buf, data, user_controlled_size)`
    Affected if No upper bound validation exists on the size parameter passed to evbuffer functions before processing

You are affected if your system runs Libevent version 1.4.0-1.4.11 (or Debian 7.0) AND any application using the evbuffer API processes potentially large external input without size limits.

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 Libevent to version 1.4.15+, 2.0.22+, or 2.1.5-beta or later to patch the integer overflow vulnerabilities in the evbuffer functions.

Fix this in Debian Linux Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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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-2014-6272 in production — separate from our analysis above.

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What this is

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What belongs here
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