CVE-2021-3907 [High] | Input Validation Bypass in Octorpki

OctoRPKI does not escape a URI with a filename containing "..", this allows a repository to create a file, (ex. rsync://example.org/repo/../../etc/cron.daily/evil.roa), which would then be written to disk outside the base cache folder. This could allow for remote code execution on the host machine OctoRPKI is running on.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-03-12	1.47%	1.89%	+0.42%
2	2026-03-04	1.84%	1.47%	-0.38%
3	2026-03-01	—	1.84%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-03-12

1.47%

1.89%

+0.42%

2026-03-04

1.84%

1.47%

-0.38%

2026-03-01

—

1.84%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.4	3.1	HIGH	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	2.2	5.2	[email protected]
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
7.5	2.0	HIGH	`AV:N/AC:L/Au:N/C:P/I:P/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	10.0	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.4

3.1

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

2.2

5.2

[email protected]

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

7.5

2.0

HIGH

AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

6.4

[email protected]

OS Trackers for CVE-2021-3907

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2021-3907 not yet assigned priority: Debian including 2 source packages (cfrpki, fort-validator), 7 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 7.	https://security-tracker.debian.org/tracker/CVE-2021-3907
`ubuntu`	medium	CVE-2021-3907 medium priority: Ubuntu including 2 source packages (cfrpki, fort-validator), 24 status rows across 14 suites (focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 14, not-affected 5, DNE 2, released 2, needed 1.	https://ubuntu.com/security/CVE-2021-3907

Affected software / configurations for CVE-2021-3907

Vendor	Product	Version	Raw CPE
cloudflare	octorpki	< 1.3.0	cpe:2.3:a:cloudflare:octorpki::::::::
debian	debian_linux	10.0	cpe:2.3:o:debian:debian_linux:10.0:::::::*
debian	debian_linux	11.0	cpe:2.3:o:debian:debian_linux:11.0:::::::*

References for CVE-2021-3907

URL	Tags
https://github.com/cloudflare/cfrpki/security/advisories/GHSA-3jhm-87m6-x959	Third Party Advisory
https://github.com/cloudflare/cfrpki/security/advisories/GHSA-cqh2-vc2f-q4fh	Third Party Advisory
https://www.debian.org/security/2021/dsa-5033	Third Party Advisory
https://www.debian.org/security/2022/dsa-5041	Third Party Advisory

URL

CVE-2021-3907 | Arbitrary filepath traversal via URI injection

Exploit prediction scoring system (EPSS) score for CVE-2021-3907

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3907

Weakness enumeration for CVE-2021-3907

GitHub Security Advisory for CVE-2021-3907

OS Trackers for CVE-2021-3907

Affected software / configurations for CVE-2021-3907

References for CVE-2021-3907