1) Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Risk: Low

CVSSv3: 3.9 [CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-15847

CWE-ID: CWE-338 - Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Exploit availability: No

Description

The vulnerability allows an attacker to bypass implemented security restrictions.

The vulnerability exists due to the POWER9 backend in GNU Compiler Collection (GCC) can optimize multiple calls of the __builtin_darn intrinsic into a single call, thus reducing the entropy of the random number generator. This vulnerability may weaken security features that rely on random number generator.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Gnu Compiler Collection: 7.1.0, 7.2.0, 7.3.0, 7.4.0, 7.5.0, 8.1.0, 8.2.0, 8.3.0, 9.1.0, 9.2.0

CPE

• cpe:/a:gnu:gcc:9.2.0:
• cpe:/a:gnu:gcc:9.1.0:
• cpe:/a:gnu:gcc:8.3.0:
• cpe:/a:gnu:gcc:8.2.0:
• cpe:/a:gnu:gcc:8.1.0:
• cpe:/a:gnu:gcc:7.5.0:
• cpe:/a:gnu:gcc:7.4.0:
• cpe:/a:gnu:gcc:7.3.0:
• cpe:/a:gnu:gcc:7.2.0:
• cpe:/a:gnu:gcc:7.1.0:

External links

http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00056.html
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00057.html
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91481
https://gcc.gnu.org/git/?p=gcc.git&a=commit;h=e99bfdd2a8db732ea84cf0a6486707e5e821ad7e

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.