#VU258 Vaudenay timing attack in OpenSSL - CVE-2003-0078

Vulnerability identifier: #VU258

Vulnerability risk: Medium

CVSSv4.0: 5.5 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2003-0078

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
OpenSSL
Server applications / Encryption software

Vendor: OpenSSL Software Foundation

Description
The vulnerability allows a remote attacker to cause an information leak.

The vulnerability exists due to ssl3_get_record in s3_pkt.c does not perform a MAC computation if an incorrect block cipher padding is used, which causes an information leak (timing discrepancy). A remote unauthenticated attacker can launch cryptographic attacks that rely on distinguishing between padding and MAC verification errors, possibly leading to extraction of the original plaintext, aka the "Vaudenay timing attack".

Successful exploitation of this vulnerability may result in disclosure of system information.

Mitigation
Upgrade your version to OpenSSL 0.9.7a, OpenSSL 0.9.6i.

Vulnerable software versions

OpenSSL: 0.9.6e - 0.9.6, 0.9.7

---

External links
https://www.openssl.org/news/vulnerabilities.html#y2002

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.