Vulnerability Details : CVE-2021-3761
Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP "MaxLength" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as "RPKI invalid". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.
Vulnerability category: Memory Corruption
Products affected by CVE-2021-3761
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
- cpe:2.3:a:cloudflare:octorpki:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-3761
0.11%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 45 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-3761
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
5.0
|
MEDIUM | AV:N/AC:L/Au:N/C:N/I:N/A:P |
10.0
|
2.9
|
NIST | |
|
7.5
|
HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
3.9
|
3.6
|
Cloudflare, Inc. | |
|
7.5
|
HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
3.9
|
3.6
|
NIST |
CWE ids for CVE-2021-3761
-
The product writes data past the end, or before the beginning, of the intended buffer.Assigned by: nvd@nist.gov (Primary)
References for CVE-2021-3761
-
https://www.debian.org/security/2022/dsa-5041
Debian -- Security Information -- DSA-5041-1 cfrpkiThird Party Advisory
-
https://github.com/cloudflare/cfrpki/security/advisories/GHSA-c8xp-8mf3-62h9
OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values · Advisory · cloudflare/cfrpki · GitHubPatch;Third Party Advisory
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