CVE-2018-15836
Consequently, a remote attacker can forge signatures when small public exponents are being used.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.52%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 1.52% probability · 74th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-347
- Affected
- xelerance/openswan
- Source
- cve@mitre.org
EPSS 1.5% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/xelerance/Openswan/commit/0b460be9e287fd335c8ce58129c67bf06065ef51Patch, Vendor Advisory
- https://github.com/xelerance/Openswan/commit/9eaa6c2a823c1d2b58913506a15f9474bf857a3dPatch, Vendor Advisory
- https://lists.openswan.org/pipermail/users/2018-August/023761.htmlRelease Notes, Vendor Advisory
- https://github.com/xelerance/Openswan/commit/0b460be9e287fd335c8ce58129c67bf06065ef51Patch, Vendor Advisory
- https://github.com/xelerance/Openswan/commit/9eaa6c2a823c1d2b58913506a15f9474bf857a3dPatch, Vendor Advisory
- https://lists.openswan.org/pipermail/users/2018-August/023761.htmlRelease Notes, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.