{"id":"GHSA-7wpf-ch8f-5f4x","kind":"vulnerability","aliases":["GHSA-7wpf-ch8f-5f4x"],"related":[],"title":"signalk-server has SSRF via absolute signalk.appIcon URL in the app store icon fetcher","description":"### Summary\n\nThe app store icon code (`dist/appstore/icon-probe.js` around line 200 and `icon-bytes.js` around line 138) resolves a plugin's declared `signalk.appIcon`. Relative paths are pinned to the CDN, but an absolute http(s) URL is used as-is: the server fetches it, follows redirects, and stores any `image/*` response as the plugin's icon, which is then served to the admin UI. Unrelated to GHSA-q59x-jc9f-gfqf.\n\n### Affected\n\nsignalk-server 2.33.0 (latest).\n\n### Reproduction\n\nThe real dist modules driven directly, Docker with `--network none`; a local \"internal\" service on 127.0.0.1 logs requests:\n\n```\n[CONTROL relative] declared=../../icon.png\n  resolved=null\n  internal-service hits: []  stored: null\n[ATTACK absolute] declared=http://127.0.0.1:35013/latest/meta-data/iam\n  resolved=http://127.0.0.1:35013/latest/meta-data/iam\n  internal-service hits: [\"GET /latest/meta-data/iam\"]  stored: .../icon-bytes/evil-plugin@1.0.0.png (70 bytes)\n[ATTACK redirect] declared=http://127.0.0.1:35013/redir\n  internal-service hits: [\"GET /redir\",\"GET /internal-secret-via-redirect.png\"]  stored: .../icon-bytes/evil-plugin@1.0.0.png (70 bytes)\n```\n\nThe modules were tested directly rather than through a full running server.\n\n### Impact\n\nAnyone who can get a plugin listed in the app store (publishing an npm package with the signalk keywords) can make every signalk-server that browses the app store send requests to internal addresses on the vessel network and to cloud metadata endpoints. Responses with an image content type are stored and served back to the user.\n\n### Suggested fix\n\nOnly accept relative icon paths resolved against the CDN (or an https allowlist of known hosts), do not follow redirects to other hosts, and reject private, loopback and link-local addresses after resolution.","summary":"signalk-server fetches the icon URL a plugin declares in its package, and accepts absolute http(s) URLs as-is and follows redirects. A malicious plugin listed in the app store can make the server request internal or cloud metadata addresses and store any image response as the plugin icon, which is then shown in the admin UI.","severity":"medium","cvss":4.2,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"signalk-server","fixed":["2.34.0"],"affected":">= 2.28.0-beta.2, < 2.34.0","ecosystem":"npm"}],"ecosystems":["npm"],"tags":["cwe-918","marine","npm","package","self-hosted","signalk-server"],"not_affected_if":["default-config"],"how_to_check":"- Check the installed version with `npm ls signalk-server` or the server's package.json; affected versions are `>= 2.28.0-beta.2` and `< 2.34.0`.\n- Look for `signalk.appIcon` values that are absolute URLs in installed plugin package.json files.","fix":"- `signalk-server` `2.34.0`","status":"open","published_at":"2026-10-30T22:57:37+00:00","first_seen_at":"2026-10-30T23:02:03+00:00","triaged_at":"2026-10-30T23:02:44+00:00","updated_at":"2026-10-30T23:02:44+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-30T23:02:44Z","model":"claude-haiku-5-5","output":{"fix":"- `signalk-server` `2.34.0`","reach":"internet","title":"signalk-server: app store icon fetch lets a plugin reach internal addresses","impact":"medium","summary":"signalk-server fetches the icon URL a plugin declares in its package, and accepts absolute http(s) URLs as-is and follows redirects. A malicious plugin listed in the app store can make the server request internal or cloud metadata addresses and store any image response as the plugin icon, which is then shown in the admin UI.","audience":"businesses","category":"package","nicknames":[],"who_cares":["signalk-server","self-hosted","npm","marine"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"internal services and cloud metadata are reached and responses stored","analyst_note":"","how_to_check":"- Check the installed version with `npm ls signalk-server` or the server's package.json; affected versions are `>= 2.28.0-beta.2` and `< 2.34.0`.\n- Look for `signalk.appIcon` values that are absolute URLs in installed plugin package.json files.","plain_action":"","needs_analyst":false,"not_affected_if":["default-config"],"who_is_affected":"Servers running signalk-server in the affected range that browse the app store and so fetch plugin icons. Exposure comes from the app store fetch path, so a server with no app store use and no outbound access to the vessel network or cloud metadata is less at risk. The sources do not say whether managed or default configurations change this.","user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"unknown"},"cost_usd":0.000764,"input_tokens":4869,"output_tokens":554,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-918':30B '/../icon.png':198C '/icon-bytes/evil-plugin':222C,240C '/internal-secret-via-redirect.png':238C '/latest/meta-data/iam':220C '/redir':236C '1.0.0.png':223C,241C '127.0.0.1':192C,210C,213C,229C '138':114C '2.33.0':174C '200':109C '35013/latest/meta-data/iam':211C,214C '35013/redir':230C '5f4x':20A,25A '70':224C,242C '7wpf':18A,23A 'absolut':7A,55B,130C,208C 'accept':54B,318C 'address':82B,291C,348C 'admin':98B,161C 'affect':170C 'allowlist':329C 'anyon':257C 'app':12A,71B,102C,266C,285C 'around':107C,112C 'as-i':59B,136C 'attack':207C,226C 'back':311C 'brows':283C 'byte':225C,243C 'cdn':127C,325C 'ch8f':19A,24A 'cloud':80B,298C 'code':105C 'content':305C 'control':195C 'cwe':29B 'declar':49B,119C,197C,209C,228C 'direct':182C,248C 'dist':179C 'dist/appstore/icon-probe.js':106C 'docker':183C 'driven':181C 'endpoint':300C 'everi':278C 'fetch':43B,141C 'fetcher':15A 'fix':316C 'follow':63B,143C,335C 'full':253C 'get':219C,235C,237C,260C 'gfqf':169C 'ghsa':17A,22A,166C 'ghsa-7wpf-ch8f-5f4x':16A,21A 'ghsa-q59x-jc9f-gfqf':165C 'hit':204C,218C,234C 'host':36B,332C,339C 'http':56B,131C 'https':328C 'icon':14A,45B,91B,104C,154C,320C 'icon-bytes.js':111C 'imag':86B,148C,304C 'impact':256C 'intern':78B,189C,202C,216C,232C,290C 'internal-servic':201C,215C,231C 'jc9f':168C 'keyword':275C 'known':331C 'latest':175C 'line':108C,113C 'link':346C 'link-loc':345C 'list':68B,263C 'local':188C,347C 'log':193C 'loopback':343C 'make':74B,277C 'malici':66B 'marin':31B 'metadata':81B,299C 'modul':180C,245C 'network':185C,295C 'none':186C 'npm':32B,270C 'null':200C,206C 'packag':33B,52B,271C 'path':122C,321C 'pin':124C 'plugin':48B,67B,90B,117C,152C,262C 'privat':342C 'publish':268C 'q59x':167C 'rather':249C 'real':178C 'redirect':64B,144C,227C,336C 'reject':341C 'relat':121C,196C,319C 'reproduct':176C 'request':77B,194C,288C 'resolut':350C 'resolv':115C,199C,212C,322C 'respons':87B,149C,301C 'run':254C 'self':35B 'self-host':34B 'send':287C 'serv':158C,310C 'server':3A,28A,39B,42B,76B,140C,173C,255C,281C 'servic':190C,203C,217C,233C 'shown':95B 'signalk':2A,27A,38B,41B,172C,274C,280C 'signalk-serv':1A,37B,40B,171C,279C 'signalk-server':26A 'signalk.appicon':8A,120C 'ssrf':5A 'store':13A,72B,84B,103C,146C,205C,221C,239C,267C,286C,308C 'suggest':315C 'summari':100C 'test':247C 'type':306C 'ui':99B,162C 'unrel':163C 'url':9A,46B,58B,133C 'use':135C 'user':314C 'vessel':294C 'via':6A","nicknames":[],"mitigations":[],"who_affected":"Servers running signalk-server in the affected range that browse the app store and so fetch plugin icons. Exposure comes from the app store fetch path, so a server with no app store use and no outbound access to the vessel network or cloud metadata is less at risk. The sources do not say whether managed or default configurations change this.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"first_public_at":"2026-10-30T22:57:37+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N","cvss_by":"GitHub","poc_count":0,"sources":[{"source":"ghsa","external_id":"GHSA-7wpf-ch8f-5f4x","url":"https://github.com/advisories/GHSA-7wpf-ch8f-5f4x","severity":"medium","published_at":"2026-10-30T22:57:37+00:00","modified_at":"2026-10-30T22:57:38+00:00","first_seen_at":"2026-10-30T23:02:03+00:00","fetched_at":"2026-10-30T23:02:03+00:00","note":null}],"documents":[{"id":26668,"url":"https://api.github.com/repos/SignalK/signalk-server/security-advisories/GHSA-7wpf-ch8f-5f4x","title":"Maintainer's advisory: api.github.com","kind":"vendor","source":"ghsa","publisher":"vendor","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Maintainer's advisory: api.github.com"},{"id":26669,"url":"https://github.com/SignalK/signalk-server/security/advisories/GHSA-7wpf-ch8f-5f4x","title":"Maintainer's advisory: github.com","kind":"vendor","source":"ghsa","publisher":"vendor","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Maintainer's advisory: github.com"},{"id":26670,"url":"https://github.com/SignalK/signalk-server/commit/535104f655304c697d535252da397948e5101dc6","title":"Patch: github.com","kind":"other","source":"ghsa","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":26671,"url":"https://github.com/SignalK/signalk-server/commit/7eeae00ac4aee5f04e21e3ff9527f57823e65a4d","title":"Patch: github.com","kind":"other","source":"ghsa","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":26672,"url":"https://github.com/SignalK/signalk-server/releases/tag/v2.34.0","title":"Release: github.com","kind":"release","source":"ghsa","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Release: github.com"}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}