// For flags

CVE-2018-0733

Incorrect CRYPTO_memcmp on HP-UX PA-RISC

Severity Score

5.9
*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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).

Debido a un error de implementación, la función CRYPTO_memcmp en PA-RISC únicamente compara el bit menos significativo o de menor peso de cada byte. Esto permite que un atacante falsifique mensajes que se considerarían como autenticados en una cantidad de intentos menor que los que aseguran las garantías de seguridad del esquema. El módulo solo se puede compilar con un ensamblador HP-UX, de forma que solo se ven afectados los PA-RISC de HP-UX. Solucionado en OpenSSL 1.1.0h (versiones 1.1.0-1.1.0g afectadas).

Constructed ASN.1 types with a recursive definition (such as can be found in PKCS7) could eventually exceed the stack given malicious input with excessive recursion. This could result in a Denial Of Service attack. There are no such structures used within SSL/TLS that come from untrusted sources so this is considered safe. Other issues were also addressed.

*Credits: Peter Waltenberg (IBM)
CVSS Scores
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2017-11-30 CVE Reserved
  • 2018-03-27 CVE Published
  • 2024-09-16 CVE Updated
  • 2025-05-19 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Openssl
Search vendor "Openssl"
 Openssl
Search vendor "Openssl" for product "Openssl"
 >= 1.1.0 <= 1.1.0g
Search vendor "Openssl" for product "Openssl" and version " >= 1.1.0 <= 1.1.0g"
-
Affected