Skip to content
Noroxi
NVD / CVE Program· CNA mitre

CVE-2021-36977: matio (aka MAT File I/O Library) 1.5.20 and 1.5.21 has a heap-based buffer overflow in H5MM_memcpy (called from H5MM_malloc and H5C_load_ent

Noroxi assessment

Priority: Monitor (action score 26/100)

  • 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: 1.4% (FIRST EPSS); higher than 74.1% of all records.
  • Anyone who can reach it over the internet 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: matio (openSUSE:Leap 15.4) 1.5.23-bp154.2.3.1; matio (SUSE:Package Hub 15 SP4) 1.5.23-bp154.2.3.1.

Low priority for now. Upgrade to matio (openSUSE:Leap 15.4) 1.5.23-bp154.2.3.1; matio (SUSE:Package Hub 15 SP4) 1.5.23-bp154.2.3.1 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

matio (aka MAT File I/O Library) 1.5.20 and 1.5.21 has a heap-based buffer overflow in H5MM_memcpy (called from H5MM_malloc and H5C_load_entry), related to use of HDF5 1.12.0.

MediumCVSS 6.5 · v3.1—No exploit Fix available
Published
Jul 20, 2021
Updated
Jun 16, 2026
EPSS
1.4% · 74th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.4%

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.

Follow CVE-2021-36977

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for matio project records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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 help

Affected 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.

VendorProduct
matio projectmatio

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • matio project matio1.5.20
  • matio project matio1.5.21

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
openSUSE:Leap 15.4matiobefore 1.5.23-bp154.2.3.11.5.23-bp154.2.3.1
SUSE:Package Hub 15 SP4matiobefore 1.5.23-bp154.2.3.11.5.23-bp154.2.3.1

Same product

matio project: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-13107Multiple integer overflows exist in MATIO before 1.5.16, related to mat.c, mat4.c, mat5.c, mat73.c, and matvar_struct.c
    40Plan
  • CVE-2019-9037An issue was discovered in libmatio.a in matio (aka MAT File I/O Library) 1.5.13.
    37Monitor
  • CVE-2019-9035An issue was discovered in libmatio.a in matio (aka MAT File I/O Library) 1.5.13.
    37Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2019-20052Dec 27, 2019 · A memory leak was discovered in Mat_VarCalloc in mat.c in matio 1.5.17 because SafeMulDims does not consider the rank==0 case.
    26Monitor
  • ← EarlierCVE-2020-36428Jul 20, 2021 · matio (aka MAT File I/O Library) 1.5.18 through 1.5.21 has a heap-based buffer overflow in ReadInt32DataDouble (called from ReadInt32Data an
    35Monitor
  • Later →CVE-2020-19497Jul 21, 2021 · Integer overflow vulnerability in Mat_VarReadNextInfo5 in mat5.c in tbeu matio (aka MAT File I/O Library) 1.5.17, allows attackers to cause
    35Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
opensuse:matio1.5.23-bp154.2.3.1 · openSUSE:Leap 15.4Package registry (OSV)
suse:matio1.5.23-bp154.2.3.1 · SUSE:Package Hub 15 SP4Package 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.

No history yet (it accumulates with the daily EPSS job).

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 researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

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

  • Anyone who can reach it over the internet 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
Network
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 Write

CVSS vector

CVSS:3.1/AV:N/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

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records