RSA Padding String Verification Bypass in Openswan

CVE-2018-15836 · MEDIUM Severity

AV:N/AC:L/AU:N/C:N/I:P/A:N

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.

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