security: validate PERCY_SERVER_ADDRESS to loopback (PER-8681, PER-8682)#1165
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security: validate PERCY_SERVER_ADDRESS to loopback (PER-8681, PER-8682)#1165Shivanshu-07 wants to merge 1 commit into
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PER-8681 (CWE-918) — PERCY_SERVER_ADDRESS was assigned to utils.percy.address with no validation, so an attacker who can set it could redirect all outbound SDK HTTP (healthcheck, snapshot upload) to an arbitrary/internal host. PER-8682 (CWE-94) — percySnapshot eval()s the @percy/dom bundle returned by utils.fetchPercyDOM(), which is fetched from utils.percy.address. With an unvalidated address that eval becomes remote code execution in the test browser. Both share one root: the address. Validate PERCY_SERVER_ADDRESS resolves to a loopback host (localhost/127.0.0.1/::1) before assigning it; otherwise warn and fall back to the @percy/sdk-utils default. The eval now only ever runs code served by the local Percy CLI. (eval itself is the standard PercyDOM-injection mechanism shared by all Percy SDKs and is left in place, now sourced safely.) Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
prklm10
approved these changes
Jun 26, 2026
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Summary
Resolves the two runtime component findings behind the percy-ember chains (deadline 2026-06-21).
PERCY_SERVER_ADDRESSinjected verbatim controls all outbound HTTP targetsevalof network-fetched JS executes arbitrary code in the test browserRoot cause (shared)
addon-test-support/@percy/ember/index.jssetutils.percy.address = SDKENV.PERCY_SERVER_ADDRESSwith no validation.percySnapshottheneval()s the@percy/dombundle returned byutils.fetchPercyDOM()— which is fetched from that address. So an attacker-controlled address both redirects all SDK traffic (SSRF) and turns theevalinto RCE in the test browser.Fix
Validate
PERCY_SERVER_ADDRESSresolves to a loopback host (localhost/127.0.0.1/::1) before assigning it; otherwise warn and fall back to the@percy/sdk-utilsdefault. Theevalnow only ever executes code served by the local Percy CLI.The
evalitself is the standard PercyDOM-injection mechanism shared by every Percy SDK and is left in place — this PR secures its source, which is the exploitable part. Documented inline.Verification
evil.example,169.254.169.254rejected).node --checkpasses.Closes PER-8681, PER-8682. Together with the CI hardening (#1164) this severs the percy-ember supply-chain → runtime chains (PER-8691/8692/8693).
🤖 Generated with Claude Code