CVE-2017-12871 [Medium] | Security Bypass in Simplesamlphp

The aesEncrypt method in lib/SimpleSAML/Utils/Crypto.php in SimpleSAMLphp 1.14.x through 1.14.11 makes it easier for context-dependent attackers to bypass the encryption protection mechanism by leveraging use of the first 16 bytes of the secret key as the initialization vector (IV).

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.09%	0.49%	+0.40%
2	2023-03-07	0.89%	0.09%	-0.80%
3	2022-02-04	—	0.89%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.09%

0.49%

+0.40%

2023-03-07

0.89%

0.09%

-0.80%

2022-02-04

—

0.89%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.9	3.0	MEDIUM	`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N` 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:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	2.2	3.6	[email protected]
4.3	2.0	MEDIUM	`AV:N/AC:M/Au:N/C:P/I:N/A:N` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:N) No availability impact.	8.6	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.9

3.0

MEDIUM

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N 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:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

2.2

3.6

[email protected]

4.3

2.0

MEDIUM

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

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:N): No availability impact.

8.6

2.9

[email protected]

OS Trackers for CVE-2017-12871

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2017-12871 not yet assigned priority: Debian including 1 source packages (simplesamlphp), 3 status rows across 3 suites (bookworm, bullseye, sid): resolved 3.	https://security-tracker.debian.org/tracker/CVE-2017-12871
`ubuntu`	medium	CVE-2017-12871 medium priority: Ubuntu including 1 source packages (simplesamlphp), 21 status rows across 21 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial, zesty): not-affected 17, DNE 1, ignored 1, needed 1, released 1.	https://ubuntu.com/security/CVE-2017-12871

Affected software / configurations for CVE-2017-12871

Vendor	Product	Version	Raw CPE
simplesamlphp	simplesamlphp	1.14.0	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.0:::::::*
simplesamlphp	simplesamlphp	1.14.1	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.1:::::::*
simplesamlphp	simplesamlphp	1.14.2	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.2:::::::*
simplesamlphp	simplesamlphp	1.14.3	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.3:::::::*
simplesamlphp	simplesamlphp	1.14.4	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.4:::::::*
simplesamlphp	simplesamlphp	1.14.5	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.5:::::::*
simplesamlphp	simplesamlphp	1.14.6	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.6:::::::*
simplesamlphp	simplesamlphp	1.14.7	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.7:::::::*
simplesamlphp	simplesamlphp	1.14.8	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.8:::::::*
simplesamlphp	simplesamlphp	1.14.9	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.9:::::::*
simplesamlphp	simplesamlphp	1.14.10	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.10:::::::*
simplesamlphp	simplesamlphp	1.14.11	cpe:2.3:a:simplesamlphp:simplesamlphp:1.14.11:::::::*

References for CVE-2017-12871

URL	Tags
https://github.com/simplesamlphp/simplesamlphp/commit/77df6a932d46daa35e364925eb73a175010dc904	Issue Tracking Patch Third Party Advisory
https://simplesamlphp.org/security/201703-02	Issue Tracking Patch Third Party Advisory

URL

CVE-2017-12871

Exploit prediction scoring system (EPSS) score for CVE-2017-12871

Common vulnerability scoring system (CVSS) metrics for CVE-2017-12871

Weakness enumeration for CVE-2017-12871

GitHub Security Advisory for CVE-2017-12871

OS Trackers for CVE-2017-12871

Affected software / configurations for CVE-2017-12871

References for CVE-2017-12871