SB2019091054 - Fedora 29 update for compat-openssl10

Security Bulletin ID SB2019091054

Severity

Low

Patch available

YES

Number of vulnerabilities 6

Exploitation vector Remote access

Highest impact Denial of service

Breakdown by Severity

Low
Medium
High
Critical

Description

This security bulletin contains information about 6 secuirty vulnerabilities.

1) Information disclosure (CVE-ID: CVE-2018-0737)

The vulnerability allows a local attacker to obtain potentially sensitive information on the target system.

The weakness exists in the RSA key generation algorithm's BN_mod_inverse() and BN_mod_exp_mont() functions due to a cache timing side channel attack. A local attacker can recover the private key.

2) Improper input validation (CVE-ID: CVE-2018-0732)

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists due to improper handling of large prime values by the affected software during key agreement operations in a Transport Layer Security (TLS) handshake using an Ephemeral Diffie-Hellman (DHE) based cipher suite. A remote attacker can send a large prime value from a malicious OpenSSL server to a targeted OpenSSL client and cause the client to stop responding while generating a key for the prime value.

3) Information disclosure (CVE-ID: CVE-2018-0734)

The vulnerability allows a local attacker to obtain potentially sensitive information.

The vulnerability exists due to unspecified flaw in Digital Signature Algorithm (DSA). A local attacker can conduct a timing side-channel attack and recover the private key, which could be used to conduct further attacks.

4) Incorrect default permissions (CVE-ID: CVE-2019-1552)

The vulnerability allows a local user to bypass security restrictions.

The vulnerability exists due to OpenSSL uses insecure by default directory with potentially insecure permissions for the OPENSSLDIR on Windows. A local user can modify OpenSSL's default configuration within the 'C:/usr/local' folder, insert CA certificates, modify (or even replace) existing engine modules and bypass security restrictions, based on OpenSSL security mechanisms.

5) Use of a broken or risky cryptographic algorithm (CVE-ID: CVE-2019-1559)

The vulnerability allows a remote attacker to decrypt sensitive information.

The vulnerability exists due to the way an application behaves, when it receives a 0-byte record with invalid padding compared to the record with an invalid MAC, which results in padding oracle. A remote attacker can decrypt data.

Successful exploitation of the vulnerability requires that the application is using "non-stitched" ciphersuites and calls SSL_shutdown() twice (first, via a BAD_RECORD_MAC and again via a CLOSE_NOTIFY).

6) Use of a broken or risky cryptographic algorithm (CVE-ID: CVE-2019-1543)

The vulnerability allows a remote attacker to gain access to encrypted data.

The vulnerability exists due to incorrect implementation of the ChaCha20-Poly1305 cipher. For messages, encrypted with this cipher, a reused nonce value is used that is susceptible to serious confidentiality and integrity attacks. If an application changes the default nonce length to be longer than 12 bytes and then makes a change to the leading bytes of the nonce expecting the new value to be a new unique nonce then such an application could inadvertently encrypt messages with a reused nonce.

This vulnerability does not affect internal usage of the cipher within OpenSSL. However if an application uses this cipher directly and sets a non-default nonce length to be longer than 12 bytes, it may be vulnerable.

Remediation

Install update from vendor's website.

References

https://bodhi.fedoraproject.org/updates/FEDORA-2019-9a0a7c0986