Improper verification of cryptographic signature in Bouncy Castle

1) Improper verification of cryptographic signature

EUVDB-ID: #VU13590

Risk: Low

CVSSv4.0: [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2016-1000342

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass signature validation process.

The JCE Provider in Bouncy Castle does not fully validate ASN.1 encoding of signature on verification within ECDSA implementation. A remote attacker can inject extra elements in the sequence making up the signature, which will be considered valid allowing an attacker to add extra data into a signed structure.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

The Bouncy Castle Crypto Package For Java: 1.41 - 1.55

CPE2.3

• cpe:2.3:a:legion_of_the_bouncy_castle:bc-java:1.41:*:*:*:*:*:*:*
• cpe:2.3:a:legion_of_the_bouncy_castle:bc-java:1.42:*:*:*:*:*:*:*
• cpe:2.3:a:legion_of_the_bouncy_castle:bc-java:1.43:*:*:*:*:*:*:*

External links

http://github.com/bcgit/bc-java/commit/843c2e60f67d71faf81d236f448ebbe56c62c647#diff-25c3c78db788365f36839b3f2d3016b9

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.