CVE-2023-20126

criticalpriority · attend · 62OT risk · highEPSS 0.367 · 98 %ileexploit · PoCDEEURUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

1 exploit · PoC

Likely / severe?

36.7% (98th) EPSS

CVSS 9.8 · critical

Is it mine?

6 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

A vulnerability in the web-based management interface of Cisco SPA112 2-Port Phone Adapters could allow an unauthenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to a missing authentication process within the firmware upgrade function. An attacker could exploit this vulnerability by upgrading an affected device to a crafted version of firmware. A successful exploit could allow the attacker to execute arbitrary code on the affected device with full privileges. Cisco has not released firmware updates to address this vulnerability.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco Analog Telephone Adaptor (ATA) Softwarecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Small Business IP Phonescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v3.19.8criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · psirt@cisco.com USexploitability 3.9 · impact 5.9

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Hsecondary · CVSS-BT (t0sche)

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · Cisco PSIRT US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-306USprimaryCWE-306US

exploits (1)

Public proof-of-concept and weaponised exploit code.

fullspectrumdev/RancidCriscoPoC for CVE-2023-20126PoC · poc_in_github

affected products (6)

Products and version ranges known to be affected.

Cisco Analog Telephone Adaptor (ATA) SPA112 2-Portall versionscert_bundDEcpe:/h:cisco:ata:spa112_2-port
Cisco Cisco Analog Telephone Adaptor (ATA) Softwareall versionscisco_csafUS
Cisco Cisco Small Business IP Phonesall versionscisco_csafUS
Cisco Cisco Small Business IP Phones≤ n/aenisa_euvdEU
Cisco Systems Inc. SPA112 2-Port Phone Adapterall versionsfstec_bduRU
cisco spa112 firmware= 1.4.1nvdUScpe:2.3:o:cisco:spa112_firmware:*:*:*:*:*:*:*:*

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-1138Cisco SPA112 2-Port Phone Adapter: Schwachstelle ermöglicht CodeausführungDeutsch2023-05-03csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Cisco SPA112 2-Port Phone Adapter ausnutzen, um beliebigen Programmcode auszuführen.
cisco-sa-spa-unauth-upgrade-UqhyTWWCisco SPA112 2-Port Phone Adapters Remote Command Execution Vulnerability2023-05-03csaf · cisco_csafUS
A vulnerability in the web-based management interface of Cisco SPA112 2-Port Phone Adapters could allow an unauthenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to a missing authentication process within the firmware upgrade function. An attacker could exploit this vulnerability by upgrading an affected device to a crafted version of firmware. A successful exploit could allow the attacker to execute arbitrary code on the affected device with full privileges. Cisco has not released firmware updates to address this vulnerability. There are no workarounds that address this vulnerability.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund cisco_csaf nvd NVD CVE.org MITRE

published 2023-05-04modified 2026-06-17

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references (5)

External citations — patches, advisories, analysis.

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