Because of an implementation bug the PA-RISC CRYPTO_memcmp function is effectively reduced to only comparing the least significant bit of each byte. This allows an attacker to forge messages that would be considered as authenticated in an amount of tries lower than that guaranteed by the security claims of the scheme. The module can only be compiled by the HP-UX assembler, so that only HP-UX PA-RISC targets are affected. Fixed in OpenSSL 1.1.0h (Affected 1.1.0-1.1.0g).
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2018-0733 from the MITRE CVE dictionary dictionary and NIST NVD.
This flaw only affects the openssl code which is compiled by the HP-UX assembler, so that only HP-UX PA-RISC arches are affected. Red Hat Enterprise Linux does not support this architecture, and therefore is not affected.
NOTE: The following CVSS v3 metrics and score provided are preliminary and subject to review.
| CVSS3 Base Score | 4.8 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | Low |
| Integrity Impact | Low |
| Availability Impact | None |
| Platform | Package | State |
|---|---|---|
| Red Hat JBoss Web Server 3 | openssl | Not affected |
| Red Hat JBoss EWS 2 | openssl | Not affected |
| Red Hat JBoss EAP 6 | openssl | Not affected |
| Red Hat JBoss EAP 5 | openssl | Not affected |
| Red Hat JBoss Core Services 1 | openssl | Not affected |
| Red Hat Enterprise Linux 7 | openssl098e | Not affected |
| Red Hat Enterprise Linux 7 | openssl | Not affected |
| Red Hat Enterprise Linux 7 | OVMF | Not affected |
| Red Hat Enterprise Linux 6 | openssl | Not affected |
| Red Hat Enterprise Linux 6 | openssl098e | Not affected |
| Red Hat Enterprise Linux 5 | openssl | Not affected |
| Red Hat Enterprise Linux 5 | openssl097a | Not affected |
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