# What is CVE-2019-11072? > CVE-2019-11072 is a critical-severity flaw (CVSS 9.8) in Lighttpd, published on 10 April 2019. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 74%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2019-11072 ## At a glance - **Verdict:** Fix this soon. Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month. - **Precursor Intelligence risk score:** 65 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes. - **Severity:** Critical (CVSS 9.8 out of 10) - **Known to be exploited:** No, not on the list of flaws known to be exploited today - **Chance of use in the next 30 days:** 74% (latest exploit-likelihood forecast) - **Published:** 10 April 2019 - **Record last updated:** 4 August 2024 - **Main product:** Lighttpd - **Affected products:** 1 ## What is CVE-2019-11072? In plain terms It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline. ### The official description lighttpd before 1.4.54 has a signed integer overflow, which might allow remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a malicious HTTP GET request, as demonstrated by mishandling of /%2F? in burl_normalize_2F_to_slash_fix in burl.c. NOTE: The developer states "The feature which can be abused to cause the crash is a new feature in lighttpd 1.4.50, and is not enabled by default. It must be explicitly configured in the config file (e.g. lighttpd.conf). Certain input will trigger an abort() in lighttpd when that feature is enabled. lighttpd detects the underflow or realloc() will fail (in both 32-bit and 64-bit executables), also detected in lighttpd. Either triggers an explicit abort() by lighttpd. This is not exploitable beyond triggering the explicit abort() with subsequent application exit. ### What kind of flaw is it? - CWE-190: Integer Overflow or Wraparound ### How an attack on it works - Where an attacker can be: Anywhere on the internet - How hard it is to pull off: Easy: no special conditions - Login needed first: No login needed - Does someone have to click: No, nobody has to do anything - What an attacker gets: Can read data, change data and take it offline Severity vector: `CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` ## Is CVE-2019-11072 being exploited? Not that we know of It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 74%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 74%, 74%, 74%, 74%, 74%, 74%, 74%. ### Timeline - 10 April 2019: Published - 4 August 2024: Record last updated - 16 June 2026: Exploit likelihood jumped ### How Precursor Intelligence ranks it CVE-2019-11072 scores **65 out of 100 (Medium)**, with the action "Plan remediation". Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less: - Evidence it is being exploited: biggest factor - How severe it is: strong factor - How widely exposed it is: smaller factor - Threat activity around it: smaller factor 85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it. ## Who is affected by CVE-2019-11072? The published record lists 1 product. - [Lighttpd](https://www.precursorintelligence.com/product/lighttpd/lighttpd) by [Lighttpd](https://www.precursorintelligence.com/vendors/lighttpd) (Application): up to 1.4.53 ## How do I fix CVE-2019-11072? 1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list. 2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisories and patch notes first in the list. 3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in. 4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood. ### References - [github.com](https://github.com/lighttpd/lighttpd1.4/commit/32120d5b8b3203fc21ccb9eafb0eaf824bb59354) (Patch, Third-party advisory) - [redmine.lighttpd.net](https://redmine.lighttpd.net/issues/2945) (Exploit, Patch, Third-party advisory) - [securityfocus.com](http://www.securityfocus.com/bid/107907) (Third-party advisory, Vulnerability database) ## Questions ### What is CVE-2019-11072? CVE-2019-11072 is a critical-severity flaw in Lighttpd, published on 10 April 2019. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline. ### How serious is CVE-2019-11072? It scores 9.8 out of 10 on the CVSS severity scale, which is critical. Our risk score for CVE-2019-11072 is 65 out of 100, which is Medium. Its action is "Plan remediation". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month. ### Is CVE-2019-11072 being exploited? It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 74%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2019-11072 affect? For Lighttpd: up to 1.4.53. ### How do I fix CVE-2019-11072? Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. ## Does CVE-2019-11072 affect you? Precursor Intelligence keeps checking for you: - **Tell us what you run.** Pick your software from a list, or let us work it out from your website. - **We match it to every flaw.** Over 400,000 published flaws, checked against your list. - **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it. - **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools. Start free (no card, nothing to install): https://www.precursorintelligence.com/register Book a demo: https://www.precursorintelligence.com/contact