#VU13586 Improper verification of cryptographic signature in The Bouncy Castle Crypto Package For Java - CVE-2016-1000338

Vulnerability identifier: #VU13586

Vulnerability risk: Low

CVSSv4.0: 1.3 [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-2016-1000338

CWE-ID: CWE-347

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
The Bouncy Castle Crypto Package For Java
Universal components / Libraries / Libraries used by multiple products

Vendor: Legion of the Bouncy Castle Inc.

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 DSA 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

---

External links
https://github.com/bcgit/bc-java/commit/b0c3ce99d43d73a096268831d0d120ffc89eac7f#diff-3679f5a9d2b939...

---

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.