CVE-2018-15836

high

Description

In verify_signed_hash() in lib/liboswkeys/signatures.c in Openswan before 2.6.50.1, the RSA implementation does not verify the value of padding string during PKCS#1 v1.5 signature verification. Consequently, a remote attacker can forge signatures when small public exponents are being used. IKEv2 signature verification is affected when RAW RSA keys are used.

References

https://lists.openswan.org/pipermail/users/2018-August/023761.html

https://github.com/xelerance/Openswan/commit/9eaa6c2a823c1d2b58913506a15f9474bf857a3d

https://github.com/xelerance/Openswan/commit/0b460be9e287fd335c8ce58129c67bf06065ef51

Details

Source: Mitre, NVD

Published: 2018-09-26

Updated: 2026-06-17

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 7.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Severity: High

EPSS

EPSS: 0.00155