Multiple vulnerabilities in mruby implementation of Ruby
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 3 |
| CVE-ID | CVE-2020-6840 CVE-2020-6838 CVE-2020-6839 |
| CWE-ID | CWE-416 CWE-121 |
| Exploitation vector | Network |
| Public exploit |
Public exploit code for vulnerability #1 is available. Public exploit code for vulnerability #2 is available. Public exploit code for vulnerability #3 is available. |
| Vulnerable software Subscribe |
mruby Universal components / Libraries / Scripting languages |
| Vendor | mruby |
Security Bulletin
This security bulletin contains information about 3 vulnerabilities.
Updated 07.08.2020
Added fixed version.
1) Use-after-free
EUVDB-ID: #VU24216
Risk: High
CVSSv3.1: 8.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]
CVE-ID: CVE-2020-6840
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in "hash_slice" in "mrbgems/mruby-hash-ext/src/hash-ext.c". A remote attacker can trigger a use-after-free error and execute arbitrary code on the system.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsmruby: 2.1.0
External linkshttp://github.com/mruby/mruby/issues/4927
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.
2) Use-after-free
EUVDB-ID: #VU24215
Risk: High
CVSSv3.1: 8.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]
CVE-ID: CVE-2020-6838
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in "hash_values_at" in "mrbgems/mruby-hash-ext/src/hash-ext.c". A remote attacker can trigger a use-after-free error and execute arbitrary code on the system.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsmruby: 2.1.0
External linkshttp://github.com/mruby/mruby/issues/4926
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.
3) Stack-based buffer overflow
EUVDB-ID: #VU24214
Risk: High
CVSSv3.1: 8.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]
CVE-ID: CVE-2020-6839
CWE-ID:
CWE-121 - Stack-based buffer overflow
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error in "mrb_str_len_to_dbl" in string.c. A remote unauthenticated attacker can trigger stack-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsmruby: 2.1.0
External linkshttp://github.com/mruby/mruby/issues/4929
http://github.com/mruby/mruby/commit/2124b9b4c95e66e63b1eb26a8dab49753b82fd6c
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.
