CVE-2021-1440

MEDIUMNVD 6.86.8—
EchelonGraph scoreMEDIUM confidence

Score 6.8 from GitHub Security Advisory published 2024-11-18. NVD baseline CVSS 6.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
6.8
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 6.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A vulnerability in the implementation of the Resource Public Key Infrastructure (RPKI) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause the Border Gateway Protocol (BGP) process to crash, resulting in a denial of service (DoS) condition. This vulnerability is due to the incorrect handling of a specific RPKI to Router (RTR) Protocol packet header. An attacker could exploit this vulnerability by compromising the RPKI validator server and sending a specifically crafted RTR packet to an affected device. Alternatively, the attacker could use man-in-the-middle techniques to impersonate the RPKI validator server and send a specifically crafted RTR response packet over the established RTR TCP connection to the affected device. A successful exploit could allow the attacker to cause a DoS condition because the BGP process could constantly restart and BGP routing could become unstable.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 XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see .

CVSS v3
6.8
EG Score
6.8(medium)
EG Risk
—
EPSS
51.9%
KEV
Not listed

Published

November 18, 2024

Last Modified

August 1, 2025

References (4)

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 46× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 22:42 UTCEG score recompute
  2. 2026-07-22 14:05 UTCEPSS rescore
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  72. 2026-05-23 18:00 UTCEG score recompute
  73. 2026-05-23 18:00 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2021-1440?
CVE-2021-1440 is a medium vulnerability published on November 18, 2024. A vulnerability in the implementation of the Resource Public Key Infrastructure (RPKI) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause the Border Gateway Protocol (BGP) process to crash, resulting in a denial of service (DoS) condition. This…
When was CVE-2021-1440 disclosed?
CVE-2021-1440 was first published in the National Vulnerability Database on November 18, 2024, with the most recent update on August 1, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-1440 actively exploited?
CVE-2021-1440 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 51.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-1440?
CVE-2021-1440 has a CVSS v3 base score of 6.8 (NVD).
How do I remediate CVE-2021-1440?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-1440, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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