CVE-2019-9942 — A sandbox information disclosure exists in Twig before 1

A sandbox information disclosure exists in Twig before 1.38.0 and 2.x before 2.7.0 because, under some circumstances, it is possible to call the __toString() method on an object even if not allowed by the security policy in place.

01What is this vulnerability?

A sandbox information disclosure exists in Twig before 1.38.0 and 2.x before 2.7.0 because, under some circumstances, it is possible to call the __toString() method on an object even if not allowed by the security policy in place.

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: 2019-03-23T14:31:53.000Z
• Last modified: 2024-08-04T22:10:08.258Z

09References

• symfony.com — https://symfony.com/blog/twig-sandbox-information-disclosure
• github.com — https://github.com/twigphp/Twig/commit/eac5422956e1dcca89a3669a03a3ff32f0502077
• www.debian.org — https://www.debian.org/security/2019/dsa-4419
• seclists.org — https://seclists.org/bugtraq/2019/Mar/60