CVE-2020-13109Public exploitNetwork attack vector

Remote code execution via unchecked IF command strings

Published May 16, 2020 · Updated Aug 4, 2024

Stack buffer overflow in Morita Shogi 64 through 2020-05-02 allows remote attackers to execute arbitrary code via built-in modem packets. The IF subcommand handler at 0x800b3e94 copies two attacker-controlled strings into fixed-size stack buffers without checking their lengths. After the game establishes an online connection and accepts login packets, an unauthenticated caller can overwrite a saved return address and redirect control flow.

CVSS severity9.8
Critical
EPSS probability4.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stack buffer overflow in Morita Shogi 64 through 2020-05-02 allows remote attackers to execute arbitrary code via built-in modem packets. The IF subcommand handler at 0x800b3e94 copies two attacker-controlled strings into fixed-size stack buffers without checking their lengths. After the game establishes an online connection and accepts login packets, an unauthenticated caller can overwrite a saved return address and redirect control flow.

The record

CVE
CVE-2020-13109
Published
May 16, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 16, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8MITRECVSS:3.0/AC:L/AV:N/A:H/C:H/I:H/PR:N/S:U/UI:N
7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo