# CVE-2020-8912: In-band key negotiation issue in AWS S3 Crypto SDK for GoLang > An attacker with write access can downgrade encryption to reveal authentication keys, allowing decryption of sensitive data in S3 buckets. - **Severity:** Low 2.5 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 11 Aug 2020 - **Updated:** 4 Aug 2024 - **Also known as:** CLEANSTART-2026-SE38317, GHSA-7f33-f4f5-xwgw, GO-2022-0635, MINI-2243-v5cf-632h, MINI-255j-mhw4-xfqj, MINI-26xf-9557-38gc, MINI-2c52-9c7g-q5v3, MINI-2f55-pc96-x7vc, MINI-2jmv-q396-5hh3, MINI-2qhr-whwc-9mg8, MINI-2w3g-f2c2-5gj4, MINI-2xvr-v6jc-xmx4, MINI-3277-m7mx-wf3v, MINI-35v3-9mmq-35cx, MINI-38ww-q6jc-8h84, MINI-3c48-2cw9-m75r, MINI-3fjm-wpmj-rrjv, MINI-3fwf-xr5p-25rg, MINI-3gvw-rm7r-wx85, MINI-3m88-xfpj-3hp6, MINI-3qfc-7fp7-64mv, MINI-3vw8-rc4q-xfr2, MINI-3ww3-4p88-6423, MINI-3x63-c623-269f, MINI-428g-2h7g-vw7q, MINI-44rg-qg74-gw8g, MINI-4537-mv78-833m, MINI-4643-grhp-xfqc, MINI-464r-3c7m-6fpx, MINI-47cx-2w7m-362f, MINI-4836-35v3-5mh8, MINI-4cc9-7j5p-6r3m, MINI-4gg6-mcrx-c9vj, MINI-4gp2-g3gw-mgrg, MINI-4grc-w528-8cv8, MINI-4j5f-qhx6-c3g7, MINI-4j8p-5vmm-56qg, MINI-4q96-5f96-7pj6, MINI-4xp5-j7xg-fj2h, MINI-5552-vvhq-vqh8, MINI-55vm-565g-p7mx, MINI-5692-6jcw-m9p7, MINI-57jv-8w93-xmhp, MINI-5f4w-gx89-gfvp, MINI-5pgf-2gw3-c5c2, MINI-5q8x-4qgm-qjfq, MINI-5r2m-774w-r9x9, MINI-5rq6-4fg8-f2qf, MINI-5v42-hcq4-5pjw, MINI-5vfv-6525-5rr7, MINI-5ww6-xf8x-vm2f, MINI-66v9-43c7-p432, MINI-6fp6-232h-f3p5, MINI-6h95-xvwj-jj94, MINI-6mv9-jr7q-5rrw, MINI-6prf-45w8-xf42, MINI-6qjw-f836-p36c, MINI-6vgj-476v-w28w, MINI-6whv-2h7w-rr85, MINI-6wv2-hrc7-v3mg, MINI-72w9-phrj-2v2f, MINI-76hg-rfv7-44hx, MINI-78fp-mq6j-43m8, MINI-796f-xphq-3838, MINI-7h22-395f-4827, MINI-7mgj-rr23-83hr, MINI-7p59-v528-c9xc, MINI-7qf4-6c9v-4p8v, MINI-7rxg-4fww-chpw, MINI-7vx2-pv5p-29r8, MINI-7w69-9p36-9p5f, MINI-82vf-vm4m-m234, MINI-85g5-98wh-xrx3, MINI-88rv-6g57-8h3p, MINI-8mr8-rwmv-6qvg, MINI-8r89-hfp5-xp3r, MINI-8vf9-x9f2-hqcx, MINI-8vgp-hjx3-99x6, MINI-8vvq-3qh8-v8c7, MINI-927r-32qx-j45f, MINI-92fv-r4m5-8hmq, MINI-93mv-8hw8-2287, MINI-97c8-2jjf-j73f, MINI-99g4-jcpp-37rq, MINI-9c6w-6hmv-79xx, MINI-9cv8-h65j-2mf9, MINI-9fv7-gwf6-p745, MINI-9gq6-27wj-472v, MINI-9hrh-9x38-9w4g, MINI-9j7p-94w9-mhq7, MINI-9rrm-j65w-wvv8, MINI-c56m-j3p5-52h6, MINI-c8g4-559c-v2cr, MINI-c988-7963-32hj, MINI-c99g-qwj3-4g39, MINI-c9p8-r372-2x3r, MINI-cmgw-hqqv-9gx6, MINI-cmvg-jg7g-p8p7, MINI-cw4x-jg48-gvq8, MINI-cwj2-mm3x-h9fx, MINI-f3w9-vrjw-ghcq, MINI-f5vv-82wr-c2x8, MINI-f6jr-fpwj-rp94, MINI-f7m7-846j-g23j, MINI-f82x-38h5-w259, MINI-f87v-wq74-75pq, MINI-f98g-q29v-ggvf, MINI-fjw7-mppp-wrwc, MINI-fm5j-6mc5-2p4x, MINI-fqq3-vm92-h799, MINI-fr7h-w434-8j7h, MINI-g25m-7jmx-43fw, MINI-g4h6-8xph-p6p7, MINI-g88j-5mr4-f286, MINI-g9g5-c9vw-43p8, MINI-gg99-p77x-2485, MINI-ghrr-86p4-cvc7, MINI-gjhj-f33f-mcm7, MINI-gm6v-h6gp-r6vq, MINI-gpc8-f373-2jpf, MINI-gqcq-g9mm-mv9j, MINI-gvhm-9rcq-cmj6, MINI-gw53-pjm4-j39x, MINI-gwc3-jf4w-qwx8, MINI-gwj4-cpg8-87vm, MINI-h2mh-27c7-2cph, MINI-h4g8-xw32-mh5c, MINI-h5ch-qr38-gqf6, MINI-h684-69v5-pmr4, MINI-h6h3-gjvg-f4mj, MINI-h8c4-hprc-797c, MINI-hcg6-c37x-5q5c, MINI-hcw9-9h4v-6qv4, MINI-hf85-x275-q4jp, MINI-hjjw-wq8g-5xg6, MINI-hp4j-p36g-g2v4, MINI-hqp4-6qwf-pvx8, MINI-hv5f-9257-c23g, MINI-hx2x-24vh-h7vw, MINI-j24p-h92m-4c52, MINI-j273-8hfr-p88x, MINI-j2w2-vv74-7qmv, MINI-j37q-965c-v446, MINI-j42q-2qr6-58g4, MINI-j54c-r48p-j33p, MINI-j5p8-rhwr-4ffg, MINI-j7mc-px22-jwfq, MINI-j9hh-729j-h8w7, MINI-jg64-6rw7-553h, MINI-jh6w-97wc-445q, MINI-jq5c-pfmf-3fj9, MINI-jq5x-4gp8-2x8m, MINI-jqrx-v9mf-4ccx, MINI-jrm4-vcqq-x8p4, MINI-jrvh-7762-2p3x, MINI-jvx2-hf8w-j2m5, MINI-m282-4mjc-m5p2, MINI-m3mm-chj2-qh7c, MINI-m3pv-4hxg-5gpf, MINI-m3wr-v4h5-v3cf, MINI-m4h3-hx4m-qcw6, MINI-m64h-q4pq-f7mh, MINI-m64m-pwrf-qh83, MINI-m8j4-7cv3-p6pw, MINI-m8j8-fhm8-547f, MINI-m9p2-qj9f-mpgw, MINI-m9w6-ghmx-g7p9, MINI-mcp2-rj27-37x4, MINI-mf5w-c5m6-cmhr, MINI-mg8v-jxw9-w39j, MINI-mgf8-7w5c-g6x6, MINI-mjjj-2rwg-vgr4, MINI-mjrg-hcqg-5333, MINI-mq47-wr34-c9x9, MINI-mxg6-ch9c-44f9, MINI-p2qj-rgmg-gwrr, MINI-p2r9-hmv5-59mr, MINI-p34p-9x8c-g4x4, MINI-p3jj-fvvh-6w3m, MINI-p4q8-c8rv-jhvc, MINI-p4x6-wrcj-7gpg, MINI-p82q-mhpf-6823, MINI-p96p-63x9-v3vq, MINI-p9m9-6xrh-cpq8, MINI-pc44-4vx3-wfgw, MINI-pghh-f2fg-22f2, MINI-pm6j-ff8c-jpqp, MINI-pprc-m89w-pfm4, MINI-pqj2-hpq2-cpcf, MINI-pr5h-vcrv-fmg4, MINI-pw7r-vmvf-648w, MINI-q49m-8g8x-ggj9, MINI-q4mc-x68h-jj6f, MINI-q77r-pgmh-wxpc, MINI-q78g-v879-27r2, MINI-q854-f2xj-6hrq, MINI-qf7j-qmh3-cfqh, MINI-qgqc-pmjc-57hr, MINI-qhg5-wxh7-rmp9, MINI-qjhc-cm67-99h8, MINI-qm4f-ch6r-j47h, MINI-qm66-v7cj-v2r9, MINI-qpvp-ggh4-fhm7, MINI-qr5q-2gc5-xw4r, MINI-qv59-5g6c-mcjj, MINI-r443-vc9v-r7jf, MINI-r6rf-7q8c-3fpg, MINI-r7rj-9vqf-56px, MINI-r96h-fx4p-x4c8, MINI-rg6f-g8jh-8fjq, MINI-rmg3-v5mv-x4j3, MINI-rp7g-245x-wfgj, MINI-rq4p-2rwm-gj2p, MINI-rq7c-89v9-5875, MINI-rqfv-2jgg-ff69, MINI-rqrp-x4g6-h6h5, MINI-rv8j-864p-4mvv, MINI-rx73-j55h-wqj6, MINI-v23g-jc24-c4rp, MINI-v5gg-mf47-6jfc, MINI-v5m7-rvvq-2j8v, MINI-v5p5-q45x-85m5, MINI-v78j-3xr9-74c8, MINI-v8cv-j8pr-3jf7, MINI-v8qp-q85m-cq4v, MINI-vffv-27hq-w5pc, MINI-vj8v-jch3-v35c, MINI-vvjc-rjgr-w23h, MINI-vwfp-8j38-pr5w, MINI-vx6q-hwjg-779h, MINI-vxpj-vfjc-9f5j, MINI-w2x2-7wvw-j7pp, MINI-w74m-3gvv-xg7q, MINI-w862-vj6j-jpq2, MINI-w8jj-w8jp-8523, MINI-w8jv-665q-7fwx, MINI-w955-v63h-76fg, MINI-wcgm-98hf-77g8, MINI-wj8r-g9cq-mr4f, MINI-wm8f-f97x-vj2v, MINI-wr3g-4rvw-gmjg, MINI-wr89-356m-4955, MINI-wx2w-57rr-49q7, MINI-x2jp-wh4r-8fg5, MINI-x3v4-g4xv-5h28, MINI-x44f-xv9g-fp7v, MINI-x5f8-h39r-7x3r, MINI-x66q-jxrh-3f8f, MINI-x95v-cq3c-gxh6, MINI-x9rh-m8h6-c6cj, MINI-xcph-ppf3-g48p, MINI-xfgx-4gj2-c3pq, MINI-xv2c-p6xq-qx4v, MINI-xwcm-jj8f-5r5q, MINI-xwqx-g5jp-64mc ## What is CVE-2020-8912? CVE-2020-8912 is a low-severity vulnerability in Google LLC AWS S3 Crypto SDK for GoLang, published on 11 Aug 2020. It can only be exploited from the same machine or local network, with no action from the victim. ### 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. Weakness: CWE-327 (Use of a Broken or Risky Cryptographic Algorithm) ## Which versions are affected by CVE-2020-8912? 3 open source packages ship an affected version, including github.com/aws/aws-sdk-go. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/aws/aws-sdk-go` | Go | All versions | None | | `github.com/aws/aws-sdk-go` | Go | All versions | 1.34.0 | | `github.com/aws/aws-sdk-go` | Go | All versions | 1.34.0 | Products: Amazon Aws S3 Crypto Sdk. ## How do I fix CVE-2020-8912? Upgrade github.com/aws/aws-sdk-go to 1.34.0 or later. ## Is CVE-2020-8912 being exploited? There is no known exploitation of CVE-2020-8912 in the wild and no public exploit code. ## Other vulnerabilities in Google LLC AWS S3 Crypto SDK for GoLang - [CVE-2020-8911](https://insights.sbomify.com/CVE-2020-8911/): CBC padding oracle in AWS S3 Crypto SDK for GoLang (medium 5.6) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2020-8912 and fix it if it is affected. What it is: CVE-2020-8912 is a low-severity vulnerability in Google LLC AWS S3 Crypto SDK for GoLang, published on 11 Aug 2020. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2020-8912 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/aws/aws-sdk-go (Go): affected all versions; no fix listed - github.com/aws/aws-sdk-go (Go): affected all versions; fixed in 1.34.0 - github.com/aws/aws-sdk-go (Go): affected all versions; fixed in 1.34.0 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2020-8912/ (Markdown: https://insights.sbomify.com/CVE-2020-8912/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8912 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8912 - OSV: https://osv.dev/vulnerability/CVE-2020-8912 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-8912/ Summaries are generated and may contain mistakes; the official description above is the record.