# What is CVE-2020-8912? > CVE-2020-8912 is a low-severity flaw (CVSS 2.5) in Aws S3 Crypto SDK from Amazon, published on 11 August 2020. 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 0.2%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.edgeprotect.io/what-is/cve-2020-8912 ## At a glance - **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle. - **EdgeProtect risk score:** 30 out of 100 (Low); action: Monitor. Kept up to date as the evidence changes. - **Severity:** Low (CVSS 2.5 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:** 0.2% (latest exploit-likelihood forecast) - **Published:** 11 August 2020 - **Record last updated:** 17 August 2020 - **Main product:** Aws S3 Crypto SDK from Amazon - **Affected products:** 1 ## What is CVE-2020-8912? In plain terms An attacker has to be already on the device with an ordinary user account, and nobody has to click anything. If it works, the attacker can read some data. ### The official description A vulnerability in the in-band key negotiation exists in the AWS S3 Crypto SDK for GoLang versions prior to V2. An attacker with write access to the targeted bucket can change the encryption algorithm of an object in the bucket, which can then allow them to change AES-GCM to AES-CTR. Using this in combination with a decryption oracle can reveal the authentication key used by AES-GCM as decrypting the GMAC tag leaves the authentication key recoverable as an algebraic equation. It is recommended to update your SDK to V2 or later, and re-encrypt your files. ### What kind of flaw is it? - CWE-327: Use of a Broken or Risky Cryptographic Algorithm ### How an attack on it works - Where an attacker can be: Already on the device - How hard it is to pull off: Hard: conditions must line up - Login needed first: An ordinary user account - Does someone have to click: No, nobody has to do anything - What an attacker gets: Can read some data Severity vector: `CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N` ## Is CVE-2020-8912 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 0.2%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 0.2%, 0.2%, 0.2%, 0.2%, 0.2%, 0.2%, 0.2%. ### Timeline - 11 August 2020: Published - 17 August 2020: Record last updated ### How EdgeProtect ranks it CVE-2020-8912 scores **30 out of 100 (Low)**, with the action "Monitor". 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: key context - Real threat activity around it: key context 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-2020-8912? The published record lists 1 product. Versions are as published: "before 2.0" means every version up to, but not including, 2.0. - [Aws S3 Crypto SDK](https://www.edgeprotect.io/product/amazon/aws_s3_crypto_sdk) by [Amazon](https://www.edgeprotect.io/vendors/amazon) (Application): before 2.0 ## How do I fix CVE-2020-8912? 1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? EdgeProtect 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 - [aws.amazon.com](https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09) (Vendor advisory) - [github.com](https://github.com/google/security-research/security/advisories/GHSA-7f33-f4f5-xwgw) (Exploit, Third-party advisory) ## Questions ### What is CVE-2020-8912? CVE-2020-8912 is a low-severity flaw in Aws S3 Crypto SDK from Amazon, published on 11 August 2020. An attacker has to be already on the device with an ordinary user account, and nobody has to click anything. If it works, the attacker can read some data. ### How serious is CVE-2020-8912? It scores 2.5 out of 10 on the CVSS severity scale, which is low. Our risk score for CVE-2020-8912 is 30 out of 100, which is Low. Its action is "Monitor". No sign of exploitation and a low forecast. Patch it in your normal update cycle. ### Is CVE-2020-8912 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 0.2%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2020-8912 affect? For Aws S3 Crypto SDK from Amazon: before 2.0. ### How do I fix CVE-2020-8912? 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-2020-8912 affect you? EdgeProtect 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.edgeprotect.io/register Book a demo: https://www.edgeprotect.io/contact