CVE-2024-20309

mediumpriority · track · 22EPSS 0.001 · 1 %ileDEEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.10% (1st) EPSS
CVSS 5.5 · medium
Is it mine?
1,489 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

A vulnerability in auxiliary asynchronous port (AUX) functions of Cisco IOS XE Software could allow an authenticated, local attacker to cause an affected device to reload or stop responding. This vulnerability is due to the incorrect handling of specific ingress traffic when flow control hardware is enabled on the AUX port. An attacker could exploit this vulnerability by reverse telnetting to the AUX port and sending specific data after connecting. A successful exploit could allow the attacker to cause the device to reset or stop responding, resulting in a denial of service (DoS) condition.

01

remediations

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

A vendor fix is available.

02

cvss

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

5.6
010

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

v3.15.5mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 3.6
v3.15.6mediumAV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
v3.15.6mediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU
v3.15.6mediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · psirt@cisco.com USexploitability 1.1 · impact 4
v3.15.1mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.15.6mediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · Cisco PSIRT US
03

ssvc

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

Trackcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-828USCWE-828US
05

affected products (1,489)

Products and version ranges known to be affected.

showing 20 of 1,489
06

advisories (2)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2024-0745Cisco IOS XE: Mehrere SchwachstellenDeutsch2024-03-27csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Cisco IOS XE ausnutzen, um beliebigen Programmcode auszuführen, Sicherheitsvorkehrungen zu umgehen, seine Privilegien zu erweitern oder einen Denial of Service Zustand herbeizuführen.

  • cisco-sa-aux-333WBz8fCisco IOS XE Software Auxiliary Asynchronous Port Denial of Service Vulnerability2024-03-27csaf · cisco_csafUS

    A vulnerability in auxiliary asynchronous port (AUX) functions of Cisco IOS XE Software could allow an authenticated, local attacker to cause an affected device to reload or stop responding. This vulnerability is due to the incorrect handling of specific ingress traffic when flow control hardware is enabled on the AUX port. An attacker could exploit this vulnerability by reverse telnetting to the AUX port and sending specific data after connecting. A successful exploit could allow the attacker to cause the device to reset or stop responding, resulting in a denial of service (DoS) condition. Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability. This advisory is part of the March 2024 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: March 2024 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75056"].

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundcisco_csafNVDCVE.orgMITRE
published 2024-03-27modified 2026-06-17
09

references (5)

External citations — patches, advisories, analysis.

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