CVE-2019-13617 — njs through 0

njs through 0.3.3, used in NGINX, has a heap-based buffer over-read in nxt_vsprintf in nxt/nxt_sprintf.c during error handling, as demonstrated by an njs_regexp_literal call that leads to an njs_parser_lexer_error call and then an njs_parser_scope_error call.

01What is this vulnerability?

njs through 0.3.3, used in NGINX, has a heap-based buffer over-read in nxt_vsprintf in nxt/nxt_sprintf.c during error handling, as demonstrated by an njs_regexp_literal call that leads to an njs_parser_lexer_error call and then an njs_parser_scope_error call.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-07-16T16:07:00.000Z
• Last modified: 2024-08-04T23:57:39.467Z

09References

• github.com — https://github.com/nginx/njs/issues/174
• bugs.chromium.org — https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=15093