Cisco IOS XR Software Additional Paths Denial of Service Vulnerability
Published Aug 17, 2020
4.3
MEDIUMCVSS 3.1
EPSS 1.06%
Description
A vulnerability in the Border Gateway Protocol (BGP) additional paths feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to prevent authorized users from monitoring the BGP status and cause the BGP process to stop processing new updates, resulting in a denial of service (DOS) condition. The vulnerability is due to an incorrect calculation of lexicographical order when displaying additional path information within Cisco IOS XR Software, which causes an infinite loop. An attacker could exploit this vulnerability by sending a specific BGP update from a BGP neighbor peer session of an affected device; an authorized user must then issue a show bgp command for the vulnerability to be exploited. A successful exploit could allow the attacker to prevent authorized users from properly monitoring the BGP status and prevent BGP from processing new updates, resulting in outdated information in the routing and forwarding tables.
Affected products
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||
|---|---|---|---|---|---|---|
| Cisco | Cisco IOS XR Software | n/a |
|
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
No CVSS v3.0 score for this CVE.
AV:N/AC:M/Au:N/C:N/I:N/A:P
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Nov 13, 2024 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Table of values (11 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 1.06% (0.01057) | 63.25th | v5 (v2026.06.15) |
| Sep 20, 2026 | 1.06% (0.01057) | 62.96th | v5 (v2026.06.15) |
| Jul 20, 2024 | 0.14% (0.00135) | 49.37th | v3 (v2023.03.01) |
| Sep 3, 2023 | 0.14% (0.00135) | 48.13th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.12% (0.00122) | 44.80th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.05% (0.01055) | 52.13th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.05% (0.01055) | 48.43th | v2 (v2022.01.01) |
| Mar 31, 2022 | 2.56% (0.02561) | 62.63th | v2 (v2022.01.01) |
| Jan 6, 2022 | 2.86% (0.02857) | 63.25th | v1 |
| Jan 5, 2022 | 0.65% (0.00651) | 47.22th | v5 (v2026.06.15) |
| Apr 14, 2021 | 0.65% (0.00651) | 0.00th | v1 |
References (1)
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-bgp-ErKEqAer vendor-advisoryx_refsource_CISCOVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-bgp-ErKEqAer | vendor-advisoryx_refsource_CISCOVendor Advisory |
Change history (0)
No recorded changes yet.