# What is CVE-2013-4983? > CVE-2013-4983 is a critical-severity flaw (CVSS 10.0) in Web Appliance Firmware from Sophos, published on 10 September 2013. 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 90%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2013-4983 ## 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:** 72 out of 100 (High); action: Patch now. Kept up to date as the evidence changes. - **Severity:** Critical (CVSS 10.0 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:** 90% (latest exploit-likelihood forecast) - **Published:** 10 September 2013 - **Record last updated:** 16 June 2026 - **Main product:** Web Appliance Firmware from Sophos - **Affected products:** 1 ## What is CVE-2013-4983? In plain terms It can be attacked from anywhere on the internet without logging in. If it works, the attacker can read data, change data and take it offline. ### The official description The get_referers function in /opt/ws/bin/sblistpack in Sophos Web Appliance before 3.7.9.1 and 3.8 before 3.8.1.1 allows remote attackers to execute arbitrary commands via shell metacharacters in the domain parameter to end-user/index.php. ### What kind of flaw is it? - CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') ### 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 - What an attacker gets: Can read data, change data and take it offline Severity vector: `AV:N/AC:L/Au:N/C:C/I:C/A:C` ## Is CVE-2013-4983 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 90%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 90%, 90%, 90%, 90%, 90%, 90%, 90%. ### Timeline - 10 September 2013: Published - 16 June 2026: Record last updated ### How Precursor Intelligence ranks it CVE-2013-4983 scores **72 out of 100 (High)**, with the action "Patch now". 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-2013-4983? The published record lists 1 product. - [Web Appliance Firmware](https://www.precursorintelligence.com/product/sophos/web_appliance_firmware) by [Sophos](https://www.precursorintelligence.com/vendors/sophos) (Application): up to 3.7.9, 3.8.0, 3.8.1 ## How do I fix CVE-2013-4983? 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 advisory 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 - [sophos.com](http://www.sophos.com/en-us/support/knowledgebase/119773.aspx) (Vendor advisory) - [coresecurity.com](http://www.coresecurity.com/advisories/sophos-web-protection-appliance-multiple-vulnerabilities) (Exploit) ## Questions ### What is CVE-2013-4983? CVE-2013-4983 is a critical-severity flaw in Web Appliance Firmware from Sophos, published on 10 September 2013. It can be attacked from anywhere on the internet without logging in. If it works, the attacker can read data, change data and take it offline. ### How serious is CVE-2013-4983? It scores 10.0 out of 10 on the CVSS severity scale, which is critical. Our risk score for CVE-2013-4983 is 72 out of 100, which is High. Its action is "Patch now". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month. ### Is CVE-2013-4983 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 90%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2013-4983 affect? For Web Appliance Firmware from Sophos: up to 3.7.9, 3.8.0, 3.8.1. ### How do I fix CVE-2013-4983? 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-2013-4983 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