CVE-2019-5143Public exploitNetwork attack vector

Authenticated code execution via time-server format string

Published Feb 25, 2020 · Updated Aug 4, 2024

Format string overflow in Moxa AWK-3131A firmware 1.13 allows remote authenticated users to execute code via a crafted time server. The iw_console conio_writestr path passes the stored time-server value to vsprintf as a format string, allowing expansion to overrun its stack buffer and overwrite return control data. Low-privilege Telnet or SSH access is sufficient, and reopening the time-server menu renders the value and triggers the overwrite.

CVSS severity8.8
High
EPSS probability4.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Format string overflow in Moxa AWK-3131A firmware 1.13 allows remote authenticated users to execute code via a crafted time server. The iw_console conio_writestr path passes the stored time-server value to vsprintf as a format string, allowing expansion to overrun its stack buffer and overwrite return control data. Low-privilege Telnet or SSH access is sufficient, and reopening the time-server menu renders the value and triggers the overwrite.

The record

CVE
CVE-2019-5143
Published
Feb 25, 2020
Updated
Aug 4, 2024
Vendor
Moxa
Product
AWK-3131A Series
Classifications
CWE-120, CWE-134, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 25, 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

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Moxa AWK-3131A Firmware version 1.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Moxa · AWK-3131A Seriesversion=Moxa AWK-3131A Firmware version 1.13

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8Cisco TalosCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NIST NVDAV:N/AC:L/Au:S/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-134Use of Externally-Controlled Format String
T1210Exploitation of Remote Services

Public exploit references

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

Technologies

Your stack

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Your stack

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