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CVE Record

CVE-2023-38253: W3m: out of bounds read in growbuf_to_str() at w3m/indep.c

An out-of-bounds read flaw was found in w3m, in the growbuf_to_Str function in indep.c. This issue may allow an attacker to cause a denial of service through a crafted HTML file.

MediumCVSS 4.7Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2023-38253 is a denial-of-service risk in w3m, a text-based web browser. A crafted HTML file can trigger an out-of-bounds read and potentially crash the program. Business impact is limited unless w3m is used in workflows that process untrusted HTML.

Executive priority

Treat this as a routine remediation item unless w3m processes untrusted HTML in automation or shared systems. It is not currently KEV-listed in the provided bundle, but crashes in operational tooling can still affect availability.

Technical view

The flaw is a CWE-125 out-of-bounds read in w3m's growbuf_to_Str/growbuf_to_str handling in indep.c. The CVSS 3.1 score is 4.7: local attack vector, high complexity, no privileges, user interaction required, and high availability impact only.

Likely exposure

Exposure is most likely on Fedora or EPEL systems with the w3m package installed and used to open untrusted HTML. The bundle lists upstream w3m as affected, Fedora and EPEL as affected, and Red Hat Enterprise Linux 6 w3m as unaffected.

Exploitation context

The source bundle does not show CISA KEV listing or evidence of active exploitation. Exploitation requires user interaction and a crafted HTML file, so opportunistic remote exploitation is not supported by the provided evidence.

Researcher notes

Version ranges are not provided in the bundle, so package-manager advisory data is needed for precise exposure. The important triage points are w3m presence, untrusted HTML handling, and whether Fedora or EPEL package updates have been applied.

Mitigation direction

  • Inventory systems with the w3m package installed.
  • Apply Fedora or EPEL package updates where applicable.
  • Check upstream w3m and vendor advisories for fixed versions.
  • Avoid opening untrusted HTML with w3m until updated.
  • Remove w3m where it is not operationally required.

Validation and detection

  • Confirm installed w3m package versions on Linux endpoints and servers.
  • Map affected hosts to Fedora, EPEL, or other package sources.
  • Review vendor advisories for available fixed package builds.
  • Verify w3m is not used in automated untrusted HTML processing.
  • Check vulnerability scanner results against package inventory.
Prepared
Confidence
medium
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-125: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2023-38253 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
4.7 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
7Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
4.7CVSS 3.1MediumCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H13.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

4.7Medium
CVSS 3.1 vector shape for CVE-2023-38253Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/aw3mSee advisoryaffected
Red HatRed Hat Enterprise Linux 6w3munaffected
FedoraExtra Packages for Enterprise Linuxw3maffected
FedoraFedoraw3maffected
Weakness

CWE details

CWE-125

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-125 · source CWE mapping

Out-of-bounds Read

Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs