CVE-2023-31998Public exploitNetwork attack vector

UPnP service interruption via undersized port array

Published Jul 18, 2023 · Updated Oct 29, 2024

Heap overflow in miniupnpd on Ubiquiti EdgeRouter 2.0.9-hotfix.6 and earlier and airCube 2.8.8 and earlier allows remote attackers to stop UPnP. The get_portmappings_in_range function leaves its 128-entry allocation capacity unchanged during reallocation, then appends additional external NAT ports beyond the heap buffer. The default miniupnpd configuration is reachable from the LAN through an SSDP-discovered TCP port and must permit adding and listing external NAT entries; the documented consequence is UPnP service interruption.

CVSS severity5.9
Medium
EPSS probability0.80%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap overflow in miniupnpd on Ubiquiti EdgeRouter 2.0.9-hotfix.6 and earlier and airCube 2.8.8 and earlier allows remote attackers to stop UPnP. The get_portmappings_in_range function leaves its 128-entry allocation capacity unchanged during reallocation, then appends additional external NAT ports beyond the heap buffer. The default miniupnpd configuration is reachable from the LAN through an SSDP-discovered TCP port and must permit adding and listing external NAT entries; the documented consequence is UPnP service interruption.

The record

CVE
CVE-2023-31998
Published
Jul 18, 2023
Updated
Oct 29, 2024
Vendor
Ubiquiti Inc.
Product
EdgeRouter
Classifications
CWE-787, CWE-120, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 18, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 29, 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=2.0.9-hotfix.6 <=2.0.9-hotfix.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Ubiquiti Inc. · EdgeRouterversion=2.0.9-hotfix.6 <=2.0.9-hotfix.6
Ubiquiti Inc. · airCubeversion=2.8.8 <=2.8.8

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.9UbiquitiCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

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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
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1499.004Application or System Exploitation

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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