njs up to 0.3.1 nxt/nxt_utf8.h String.prototype.toBytes Negative Argument numeric error

CVSS Meta Temp Score
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CTI Interest Score
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A vulnerability was found in njs up to 0.3.1. It has been rated as problematic. This issue affects the function String.prototype.toBytes of the file nxt/nxt_utf8.h. The manipulation as part of a Negative Argument leads to a numeric error vulnerability. Using CWE to declare the problem leads to CWE-189. Impacted is availability. The summary by CVE is:

njs through 0.3.1, used in NGINX, has a segmentation fault in String.prototype.toBytes for negative arguments, related to nxt_utf8_next in nxt/nxt_utf8.h and njs_string_offset in njs/njs_string.c.

The bug was discovered 05/07/2019. The weakness was released 05/09/2019. The identification of this vulnerability is CVE-2019-11837 since 05/09/2019. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability was handled as a non-public zero-day exploit for at least 2 days. During that time the estimated underground price was around $0-$5k.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.


  • Nginx




CPE 2.3info

CPE 2.2info


VulDB CVSS-B Score: 🔍
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VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍



VulDB Base Score: 🔍
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Class: Numeric error
CWE: CWE-189

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍


Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍


Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍


05/07/2019 🔍
05/09/2019 +2 days 🔍
05/09/2019 +0 days 🔍
05/10/2019 +1 days 🔍
09/15/2023 +1589 days 🔍


Status: Not defined

CVE: CVE-2019-11837 (🔍)


Created: 05/10/2019 06:39 AM
Updated: 09/15/2023 10:35 AM
Changes: 05/10/2019 06:39 AM (57), 06/08/2020 03:12 PM (1), 09/15/2023 10:35 AM (3)
Complete: 🔍
Cache ID: 100:832:40


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