HOMEVULNERABILITIESCVE-2023-4255
MEDIUM

CVE-2023-4255

CWE-787Published: December 21, 2023· Updated: Jun 17, 2026

5.5
CVSS v3.1

Official Description

An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.

NVD Source

Technical Analysis

CVE-2023-4255 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 5.5.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected Vendors & Products

Fedora2 product(s)
extra packages for enterprise linuxfedora
tats1 product(s)
w3m
Source: NVD CPE · 5 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/tats/w3m/commit/edc602651c506aeeb60544b55534dd1722a340d3
PATCHhttps://github.com/tats/w3m/issues/268
PATCHhttps://github.com/tats/w3m/pull/273
PATCHhttps://github.com/tats/w3m/commit/edc602651c506aeeb60544b55534dd1722a340d3
PATCHhttps://github.com/tats/w3m/issues/268
PATCHhttps://github.com/tats/w3m/pull/273
ADVISORYhttps://bugzilla.redhat.com/show_bug.cgi?id=2255207
ADVISORYhttps://bugzilla.redhat.com/show_bug.cgi?id=2255207

All References (14)

→
https://bugzilla.redhat.com/show_bug.cgi?id=2255207Issue Tracking · Third Party Advisory
→
https://github.com/tats/w3m/commit/edc602651c506aeeb60544b55534dd1722a340d3Patch
→
https://github.com/tats/w3m/issues/268Exploit · Issue Tracking · Patch
→
https://github.com/tats/w3m/pull/273Issue Tracking · Patch
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/AULOBQJLXE2KCT5UVQMKGEFL4GFIAOED/
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/MKFZQUK7FPWWJQYICDZZ4YWIPUPQ2D3R/
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/TODROGVCWZ435HQIZE6ARQC5LPQLIA5C/
→
https://bugzilla.redhat.com/show_bug.cgi?id=2255207Issue Tracking · Third Party Advisory
→
https://github.com/tats/w3m/commit/edc602651c506aeeb60544b55534dd1722a340d3Patch
→
https://github.com/tats/w3m/issues/268Exploit · Issue Tracking · Patch
→
https://github.com/tats/w3m/pull/273Issue Tracking · Patch
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/AULOBQJLXE2KCT5UVQMKGEFL4GFIAOED/
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/MKFZQUK7FPWWJQYICDZZ4YWIPUPQ2D3R/
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/TODROGVCWZ435HQIZE6ARQC5LPQLIA5C/

Quick Facts

CVE IDCVE-2023-4255
CVSS Score5.5 / 10
SeverityMEDIUM
WeaknessCWE-787
CISA KEVNo
Affected2 vendor(s)
PublishedDec 21, 2023

Related CVEs (CWE-787)

CVE-2015-0235
10.0
CVE-2004-0574
10.0
CVE-2019-5049
10.0
CVE-2022-30292
10.0
CVE-2004-1287
10.0
CVE-2012-0751
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2023-4255 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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