W3m: out-of-bounds write in function checktype() in etc.c (incomplete fix for cve-2022-38223)
Noroxi assessment
Priority: Monitor (action score 22/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.32% (FIRST EPSS).
- Someone with local access to the system can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
- Fixed version: w3m (Debian:13) 0.5.3+git20230121-2.1; w3m (SUSE:Linux Enterprise Server 12 SP5) 0.5.3.git20161120-161.9.1.
Low priority for now. Upgrade to w3m (Debian:13) 0.5.3+git20230121-2.1; w3m (SUSE:Linux Enterprise Server 12 SP5) 0.5.3.git20161120-161.9.1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Dec 21, 2023
- Updated
- Jun 17, 2026
- EPSS
- 0.3% · 23th percentile
- CWE
- CWE-787
Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CNA vs NVD score
- NVD
- 5.5
- CNA · redhat
- 5.5
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| tats | w3m | cpe:2.3:a:tats:w3m |
| fedoraproject | extra packages for enterprise linux | cpe:2.3:a:fedoraproject:extra_packages_for_enterprise_linux |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- fedoraproject extra packages for enterprise linux8.0
- fedoraproject fedora39
- tats w3m0.5.3+git20230121-1
- tats w3m0.5.3+git20230121-2
- tats w3m0.5.3+git20230129
Versions reported by the vendor
Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.
Fedora Extra Packages for Enterprise Linux
- all versionsaffected
Fedora Fedora
- all versionsaffected
n/a w3m
- all versionsaffected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | w3m | from 0 | — |
| Debian:13 | w3m | before 0.5.3+git20230121-2.1 | 0.5.3+git20230121-2.1 |
| SUSE:Linux Enterprise Server 12 SP5 | w3m | before 0.5.3.git20161120-161.9.1 | 0.5.3.git20161120-161.9.1 |
Same product
tats: all recordsOther highest-scoring records for the same primary product.
- CVE-2016-9429An issue was discovered in the Tatsuya Kinoshita w3m fork before 0.5.3-31.36Monitor
- CVE-2016-9428An issue was discovered in the Tatsuya Kinoshita w3m fork before 0.5.3-31.36Monitor
- CVE-2016-9426An issue was discovered in the Tatsuya Kinoshita w3m fork before 0.5.3-31.36Monitor
Published before and after this one in the same product
- ← EarlierCVE-2022-38223Aug 15, 2022 · There is an out-of-bounds write in checkType located in etc.c in w3m 0.5.3.31Monitor
- ← EarlierCVE-2023-38252Jul 14, 2023 · W3m: out of bounds read in strnew_size() at w3m/str.c22Monitor
- ← EarlierCVE-2023-38253Jul 14, 2023 · W3m: out of bounds read in growbuf_to_str() at w3m/indep.c22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:w3m | 0.5.3+git20230121-2.1 · Debian:13 | Package registry (OSV) |
| suse:w3m | 0.5.3.git20161120-161.9.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2022-38223493 days apartThere is an out-of-bounds write in checkType located in etc.c in w3m 0.5.3.31Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-787 · Out-of-bounds WriteCVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (5 more)Show less
- github.com/tats/w3m/commit/edc602651c506aeeb60544b55534dd1722a340d3
- github.com/tats/w3m/pull/273
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/AULOBQJLXE2KCT5UVQMKGEFL4GFIAOED/
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MKFZQUK7FPWWJQYICDZZ4YWIPUPQ2D3R/
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TODROGVCWZ435HQIZE6ARQC5LPQLIA5C/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.