CVE-2021-3908
Infinite certificate chain depth results in OctoRPKI running forever
OctoRPKI does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, thereby making tree traversal never end.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Infinite certificate chain depth results in OctoRPKI running forever
OctoRPKI does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, thereby making tree traversal never end.
- Record
CVE-2021-3908- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
EUVDEUVD-2021-2345
OctoRPKI does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, thereby making tree traversal never end.
- Record
EUVD-2021-2345- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-g5gj-9ggf-9vmq
Infinite certificate chain depth results in OctoRPKI running forever
OctoRPKI (github.com/cloudflare/cfrpki/cmd/octorpki) does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, thereby making tree traversal never end.
For more information
If you have any questions or comments about this advisory email us at [email protected]
- Record
GHSA-g5gj-9ggf-9vmq- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-835
- Updated
- 2026-11-02
NVD
OctoRPKI does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, thereby making tree traversal never end.
- Record
CVE-2021-3908- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-400, CWE-835
- Updated
- 2026-11-02
OSV
OctoRPKI does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, thereby making tree traversal never end.
- Record
CVE-2021-3908- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-3908
OctoRPKI does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, thereby making tree traversal never end.
- Record
DEBIAN-CVE-2021-3908- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVGHSA-g5gj-9ggf-9vmq
Infinite certificate chain depth results in OctoRPKI running forever
OctoRPKI (github.com/cloudflare/cfrpki/cmd/octorpki) does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, thereby making tree traversal never end.
For more information
If you have any questions or comments about this advisory email us at [email protected]
- Record
GHSA-g5gj-9ggf-9vmq- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400, CWE-835
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-3908
OctoRPKI does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, thereby making tree traversal never end.
- Record
UBUNTU-CVE-2021-3908- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVGO-2022-0249 No score
Infinite certificate chain depth results in OctoRPKI running forever in github.com/cloudflare/cfrpki
Infinite certificate chain depth results in OctoRPKI running forever in github.com/cloudflare/cfrpki
- Record
GO-2022-0249- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/cloudflare/cfrpkiGo |
before 1.4.0 | 1.4.0 |
cfrpkiDebian:12 |
before 1.4.0-1 | 1.4.0-1 |
cfrpkiDebian:11 From an advisory covering 10 CVEs |
before 1.4.2-1~deb11u1, plus listed versions 1.2.2-11.3.0-11.4.0-1 |
1.4.2-1~deb11u1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-3908 is a medium vulnerability (CVSS 5.9) in Cloudflare Octorpki, published November 10, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.73%, the 54th percentile. Fixed in github.com/cloudflare/cfrpki 1.4.0.