Denial of service in LibSass
| Risk | Low |
| Patch available | YES |
| Number of vulnerabilities | 4 |
| CVE-ID | CVE-2018-19837 CVE-2018-19838 CVE-2018-19839 CVE-2018-20190 |
| CWE-ID | CWE-121 CWE-126 CWE-476 |
| 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. Public exploit code for vulnerability #4 is available. |
| Vulnerable software Subscribe |
LibSass Universal components / Libraries / Libraries used by multiple products |
| Vendor | Sass |
Security Bulletin
This security bulletin contains information about 4 vulnerabilities.
1) Stack-based buffer overflow
EUVDB-ID: #VU16232
Risk: Low
CVSSv3.1: 4.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C]
CVE-ID: CVE-2018-19837
CWE-ID:
CWE-121 - Stack-based buffer overflow
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to cause DoS condition.
The vulnerability exists due to stack-based buffer overflow in Sass::Eval::operator()(Sass::Binary_Expression*) inside eval.cpp when incorrect parsing of '%' as a modulo operator in parser.cpp. A remote attacker can send a specially crafted sass file, trigger memory corruption and cause the service to crash.
MitigationUpdate to version 3.5.5.
Vulnerable software versionsLibSass: 3.4.0 - 3.5.4
External linkshttp://github.com/sass/libsass/issues/2659
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) Stack-based buffer overflow
EUVDB-ID: #VU16233
Risk: Low
CVSSv3.1: 4.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C]
CVE-ID: CVE-2018-19838
CWE-ID:
CWE-121 - Stack-based buffer overflow
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to cause DoS condition.
The vulnerability exists due to stack-based buffer overflow in functions inside ast.cpp for IMPLEMENT_AST_OPERATORS expansion, as demonstrated by recursive calls involving clone(), cloneChildren(), and copy(). A remote attacker can send a specially crafted sass file, trigger memory corruption and cause the service to crash.
MitigationUpdate to version 3.5.5.
Vulnerable software versionsLibSass: 3.4.0 - 3.5.4
External linkshttp://github.com/sass/libsass/issues/2660
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) Heap-based buffer over-read
EUVDB-ID: #VU16234
Risk: Low
CVSSv3.1: 4.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C]
CVE-ID: CVE-2018-19839
CWE-ID:
CWE-126 - Buffer over-read
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to cause DoS condition.
The vulnerability exists due to heap-based buffer over-read in the function handle_error in sass_context.cpp. A remote attacker can send a specially crafted sass file, trigger memory corruption and cause the service to crash.
MitigationUpdate to version 3.5.5.
Vulnerable software versionsLibSass: 3.4.0 - 3.5.4
External linkshttp://github.com/sass/libsass/issues/2657
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.
4) NULL pointer dereference
EUVDB-ID: #VU16659
Risk: Low
CVSSv3.1: 6.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:P/RL:U/RC:C]
CVE-ID: CVE-2018-20190
CWE-ID:
CWE-476 - NULL Pointer Dereference
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in the function Sass::Eval::operator()(Sass::Supports_Operator*) in eval.cpp. A remote attacker can trick the victim into opening a specially crafted sass input file and perform a denial of service (DoS) attack.
MitigationCybersecurity Help is currently unaware of any official solution to address the vulnerability.
Vulnerable software versionsLibSass: 3.5.5
External linkshttp://github.com/sass/libsass/issues/2786
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.
