How severe is CVE-2022-20849?

CVE-2022-20849 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2022-20849 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2022-20849?

CVE-2022-20849 primarily affects Cisco Ios Xr. In total, 33 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2022-20849?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2022-20849 have an EU (EUVD) identifier?

Yes. CVE-2022-20849 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2022-26099.

When was CVE-2022-20849 published?

CVE-2022-20849 was published on 2024-11-15 and last updated on 2026-06-17.

CVE-2022-20849

CVE-2022-20849 is a medium-severity vulnerability in Cisco Ios Xr with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-391.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2022-26099
Weakness: CWE-391
Affected product: Cisco Ios Xr
Published: 2024-11-15
Last modified: 2026-06-17

Description

A vulnerability in the Broadband Network Gateway PPP over Ethernet (PPPoE) feature of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause the PPPoE process to continually crash. This vulnerability exists because the PPPoE feature does not properly handle an error condition within a specific crafted packet sequence. An attacker could exploit this vulnerability by sending a sequence of specific PPPoE packets from controlled customer premises equipment (CPE). A successful exploit could allow the attacker to cause the PPPoE process to continually restart, resulting in a denial of service condition (DoS).Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.This advisory is part of the September 2022 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see .

Frequently asked questions

What is CVE-2022-20849?: A vulnerability in the Broadband Network Gateway PPP over Ethernet (PPPoE) feature of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause the PPPoE process to continually crash. This vulnerability exists because the PPPoE feature does not properly handle an error condition within a specific crafted packet sequence. An attacker could exploit this vulnerability by sending a sequence of specific PPPoE packets from controlled customer premises equipment (CPE). A successful exploit could allow the attacker to cause the PPPoE process to continually restart, resulting in a denial of service condition (DoS).Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.This advisory is part of the September 2022 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see .
How severe is CVE-2022-20849?: CVE-2022-20849 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2022-20849 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-20849?: CVE-2022-20849 primarily affects Cisco Ios Xr. In total, 33 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2022-20849?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2022-20849 have an EU (EUVD) identifier?: Yes. CVE-2022-20849 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2022-26099.
When was CVE-2022-20849 published?: CVE-2022-20849 was published on 2024-11-15 and last updated on 2026-06-17.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-bng-Gmg5Gxt

Affected products (33)

cpe:2.3:o:cisco:ios_xr:6.5.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.5.15:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.6.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.6.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.6.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.6.4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.6.25:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.7.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.7.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.7.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.7.35:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.8.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.8.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:6.9.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.0.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.0.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.0.90:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.1.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.1.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.1.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.1.15:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.1.25:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.2.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.2.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.3.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.3.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.3.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.3.4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.4.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.4.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xr:7.5.1:*:*:*:*:*:*:*

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