CVE-2018-0739

libssl1.0.0: Constructed ASN.1 types with a recursive definition (such as can be found in PKCS7) could eventually exceed the stack...

CVE-2018-0739 is fixed in 4 products on 1 platform, first by libssl1.0.0 1.0.2n-1ubuntu5, released March 26, 2018. It is not reported as exploited. Patch Radar priority: Routine.

Routine
CVSS
n/a
Medium
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.1860
97th percentile

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. Fixed in OpenSSL 1.1.0h (Affected 1.1.0-1.1.0g). Fixed in OpenSSL 1.0.2o (Affected 1.0.2b-1.0.2n).

Where it's fixed

ProductFixed inFixReleased
Linux
libssl1.0.0 · Ubuntu 18.04.6 LTS (bionic) 1.0.2n-1ubuntu5 libssl1.0.0 1.0.2n-1ubuntu5 Mar 26, 2018
libssl1.1 · Ubuntu 18.04.6 LTS (bionic) 1.1.0g-2ubuntu3 libssl1.1 1.1.0g-2ubuntu3 Mar 26, 2018
openssl · Ubuntu 18.04.6 LTS (bionic) 1.1.0g-2ubuntu3 openssl 1.1.0g-2ubuntu3 Mar 26, 2018
openssl1.0 · Ubuntu 18.04.6 LTS (bionic) 1.0.2n-1ubuntu5 openssl1.0 1.0.2n-1ubuntu5 Mar 26, 2018