CVE-2021-34703

mediumPriorität · verfolgen · 26EPSS 0.012 · 68. PerzentilEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
1.19% (68th) EPSS
CVSS 6.8 · medium
Is it mine?
1,359 products
Prüfe deine Angriffsfläche
Who says so?
4 sources
cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · bewertet 2026-10-27

A vulnerability in the Link Layer Discovery Protocol (LLDP) message parser of Cisco IOS Software and Cisco IOS XE Software could allow an attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to improper initialization of a buffer. An attacker could exploit this vulnerability via any of the following methods: An authenticated, remote attacker could access the LLDP neighbor table via either the CLI or SNMP while the device is in a specific state. An unauthenticated, adjacent attacker could corrupt the LLDP neighbor table by injecting specific LLDP frames into the network and then waiting for an administrator of the device or a network management system (NMS) managing the device to retrieve the LLDP neighbor table of the device via either the CLI or SNMP. An authenticated, adjacent attacker with SNMP read-only credentials or low privileges on the device CLI could corrupt the LLDP neighbor table by injecting specific LLDP frames into the network and then accessing the LLDP neighbor table via either the CLI or SNMP. A successful exploit could allow the attacker to cause the affected device to crash, resulting in a reload of the device.

01

Behebungen

Hersteller-Fix, Mitigation oder Workaround, wie von den Quellen veröffentlicht.

Ein Hersteller-Fix ist verfügbar.

02

cvss

Technischer Schweregrad, 0–10. Eine Zeile je Quelle.

6.8
010

Basiswert 0–10 · höher = schwerwiegender · Vektor überfahren zum Auflösen

v2.06.8mediumAV:N/AC:L/Au:S/C:N/I:N/A:Cprimary · NVD / NIST USAusnutzbarkeit 8 · Auswirkung 6.9
v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USAusnutzbarkeit 2.8 · Auswirkung 3.6
v3.16.8mediumAV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
v3.16.8mediumCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU
v3.16.8mediumCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · psirt@cisco.com USAusnutzbarkeit 2.3 · Auswirkung 4
v3.16mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.16.8mediumCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hsecondary · Cisco PSIRT US
03

SSVC

Eine Handlungsentscheidung — aus Ausnutzung und Auswirkung.

Trackcoordinatorcisa_ssvcUS
04

schwächen

Die CWE-Schwächeklassen, zu denen dies gehört.

CWE-665USprimärCWE-456USCWE-456USCWE-665US
05

betroffene Produkte (1,359)

Betroffene Produkte und Versionsbereiche.

20 von 1,359 angezeigt
06

Advisories (1)

Hersteller- und Ökosystem-Meldungen dazu.

  • cisco-sa-lldp-dos-sBnuHSjTCisco IOS and IOS XE Software Link Layer Discovery Protocol Denial of Service Vulnerability2021-09-22csaf · cisco_csafUS

    A vulnerability in the Link Layer Discovery Protocol (LLDP) message parser of Cisco IOS Software and Cisco IOS XE Software could allow an attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to improper initialization of a buffer. An attacker could exploit this vulnerability via any of the following methods: An authenticated, remote attacker could access the LLDP neighbor table via either the CLI or SNMP while the device is in a specific state. An unauthenticated, adjacent attacker could corrupt the LLDP neighbor table by injecting specific LLDP frames into the network and then waiting for an administrator of the device or a network management system (NMS) managing the device to retrieve the LLDP neighbor table of the device via either the CLI or SNMP. An authenticated, adjacent attacker with SNMP read-only credentials or low privileges on the device CLI could corrupt the LLDP neighbor table by injecting specific LLDP frames into the network and then accessing the LLDP neighbor table via either the CLI or SNMP. A successful exploit could allow the attacker to cause the affected device to crash, resulting in a reload of the device. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the September 2021 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: September 2021 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication. ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74581"]

07

auch bekannt als (4)

Weitere Namen und Kennungen dieser Entität.

08

quellen

Welche Quellen diesen Datensatz belegen und wann.

cnnvdenisa_euvdfstec_bducisco_csafNVDCVE.orgMITRE
veröffentlicht 2021-09-23geändert 2026-06-17
10

Referenzen (6)

Externe Belege — Patches, Meldungen, Analysen.

scry

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