{"id":"GHSA-c8w6-x74f-vmg3","kind":"vulnerability","aliases":["GHSA-c8w6-x74f-vmg3"],"related":[],"title":"zebrad vulnerable to full node denial of service via crafted Sapling receiver in z_listunifiedreceivers","description":"### Am I affected\n\nYou are affected if:\n\n1. You run `zebrad` up to and including `v4.4.1`.\n2. Your `zebrad.toml` sets `rpc.listen_addr` to a TCP address (RPC server is enabled).\n3. An attacker can authenticate to the RPC endpoint. With the default `enable_cookie_auth = true`, this requires the attacker to read the `.cookie` file (typically local access). With `enable_cookie_auth = false`, any network client reaching the RPC port can trigger it.\n\n### Summary\n\nThe `z_listunifiedreceivers` RPC handler panics when processing a structurally valid Unified Address whose Sapling receiver carries 43 bytes that fail cryptographic validation (`sapling_crypto::PaymentAddress::from_bytes` returns `None` for non-subgroup Jubjub points). The handler calls `.expect(\"using data already decoded as valid\")` on the fallible result. Because Zebra's release profile sets `panic = \"abort\"`, the panic terminates the entire node process, not just the RPC task.\n\n### Details\n\n`zcash_address::unified::Encoding::decode` validates only the structural envelope of a Unified Address (F4Jumble, bech32m, typecode ordering, 43-byte length for Sapling). It does not validate that the embedded `pk_d` is a valid Jubjub subgroup point or that the diversifier produces a valid `g_d` preimage.\n\nAt `zebra-rpc/src/methods.rs:2893`, the handler calls `Address::try_from_sapling(network, data)`, which delegates to `sapling_crypto::PaymentAddress::from_bytes`. When `from_bytes` returns `None` (most random 32-byte strings fail the subgroup check), the `.expect()` fires and the process aborts.\n\nThe same crate already handles this correctly in `try_from_unified` at `zebra-chain/src/primitives/address.rs:99-110`, which returns `Err` when `from_bytes` fails. The vulnerable code path bypasses this validated route.\n\n### Patches\n\nzebra-rpc 8.0.0 and zebrad 4.5.0.\n\nReplace `.expect()` with `.map_err(|e| ErrorObject::owned(...))` for proper error propagation, or route through the existing `try_from_unified` path which already handles this case correctly.\n\n### Workarounds\n\n- Disable the RPC server by removing `rpc.listen_addr` from `zebrad.toml`.\n- Ensure `enable_cookie_auth = true` (the default) and restrict filesystem access to the `.cookie` file.\n- Place a reverse proxy in front of the RPC port that rejects `z_listunifiedreceivers` calls with untrusted address parameters.\n\n### Impact\n\nA single authenticated RPC request terminates the `zebrad` process. The attack is repeatable on restart (the same request triggers the same abort), allowing an attacker to keep the node down indefinitely until the request is filtered upstream. Operators using `lightwalletd` backends, Zaino indexers, or mining pool infrastructure that forward RPC calls to `zebrad` may be exposed if the forwarding path passes through `z_listunifiedreceivers`.\n\n### Credit\n\nReported by `@robustfengbin` via a private GitHub Security Advisory submission.","summary":"A crafted Unified Address passed to the z_listunifiedreceivers RPC call makes the zebrad process panic and exit. A single authenticated request keeps the node down until restarted and the request is filtered.","severity":"medium","cvss":6.5,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"zebra-rpc","fixed":["8.0.0"],"affected":"<= 7.0.0","ecosystem":"cargo"},{"name":"zebrad","fixed":["4.5.0"],"affected":"<= 4.4.1","ecosystem":"cargo"}],"ecosystems":["cargo"],"tags":["cwe-20","cwe-248","cwe-617","cwe-754","lightwalletd","mining-pool","package","zcash","zebra-rpc","zebrad"],"not_affected_if":["cookie-auth-default","no-forwarding-of-z_listunifiedreceivers","rpc-disabled"],"how_to_check":"- Check the installed version with `zebrad --version`; affected versions are up to and including `4.4.1`.\n- Look in `zebrad.toml` for `rpc.listen_addr`; the RPC server is only exposed when it is set.\n- Check whether `enable_cookie_auth` is `true` (the default) or `false`; with `false`, any network client reaching the RPC port can trigger the crash.","fix":"- `zebrad`: upgrade to `4.5.0`.\n- `zebra-rpc` (cargo): upgrade to `8.0.0`.","status":"open","published_at":"2026-07-02T19:37:58+00:00","first_seen_at":"2026-11-13T02:48:40+00:00","triaged_at":"2026-11-13T02:49:09+00:00","updated_at":"2026-11-13T02:49:09+00:00","category":"package","confidence":0.85,"triage":{"at":"2026-11-13T02:49:09Z","model":"claude-haiku-5-5","output":{"fix":"- `zebrad`: upgrade to `4.5.0`.\n- `zebra-rpc` (cargo): upgrade to `8.0.0`.","reach":"network","title":"Zebra: crafted Sapling address in RPC crashes the whole node","impact":"medium","summary":"A crafted Unified Address passed to the z_listunifiedreceivers RPC call makes the zebrad process panic and exit. A single authenticated request keeps the node down until restarted and the request is filtered.","audience":"businesses","category":"package","nicknames":[],"who_cares":["zebrad","zcash","zebra-rpc","lightwalletd","mining-pool"],"confidence":0.85,"fix_status":"available","needs_auth":"yes","worst_case":"Remote RPC request crashes the entire zebrad node process repeatedly.","analyst_note":"","how_to_check":"- Check the installed version with `zebrad --version`; affected versions are up to and including `4.4.1`.\n- Look in `zebrad.toml` for `rpc.listen_addr`; the RPC server is only exposed when it is set.\n- Check whether `enable_cookie_auth` is `true` (the default) or `false`; with `false`, any network client reaching the RPC port can trigger the crash.","plain_action":"","product_name":"","needs_analyst":false,"not_affected_if":["rpc-disabled","cookie-auth-default","no-forwarding-of-z_listunifiedreceivers"],"who_is_affected":"Only nodes running zebrad with the RPC server enabled are exposed. With the default cookie auth, an attacker needs local read access to the .cookie file; with cookie auth disabled, any network client that can reach the RPC port can trigger the crash. Lightwalletd backends, Zaino indexers and mining pool setups that forward RPC calls to zebrad may be exposed if z_listunifiedreceivers is reachable through them.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000922,"input_tokens":5697,"output_tokens":704,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-110':335C '-20':31B '-248':33B '-617':35B '-754':37B '/src/methods.rs':278C '/src/primitives/address.rs':333C '1':88C '2':97C '2893':279C '3':111C '32':304C '4.5.0':358C '43':172C,244C '8.0.0':355C '99':334C 'abort':212C,317C,453C 'access':138C,407C 'addr':102C,394C 'address':51B,106C,167C,227C,239C,283C,429C 'advisori':505C 'affect':83C,86C 'allow':454C 'alreadi':197C,321C,381C 'attack':113C,130C,442C,456C 'auth':125C,142C,400C 'authent':68B,115C,434C 'backend':472C 'bech32m':241C 'bypass':347C 'byte':173C,182C,245C,296C,299C,305C,341C 'c8w6':18A,23A 'call':58B,193C,282C,426C,482C 'carri':171C 'case':384C 'chain':332C 'check':310C 'client':146C 'code':345C 'cooki':124C,134C,141C,399C,410C 'correct':324C,385C 'craft':10A,49B 'crate':320C 'credit':496C 'crypto':179C,293C 'cryptograph':176C 'cwe':30B,32B,34B,36B 'd':257C,272C 'data':196C,288C 'decod':198C,230C 'default':122C,403C 'deleg':290C 'denial':6A 'detail':225C 'disabl':387C 'diversifi':267C 'e':364C 'embed':255C 'enabl':110C,123C,140C,398C 'encod':229C 'endpoint':119C 'ensur':397C 'entir':217C 'envelop':235C 'err':338C,363C 'error':369C 'errorobject':365C 'exist':375C 'exit':65B 'expect':194C,312C,360C 'expos':487C 'f4jumble':240C 'fail':175C,307C,342C 'fallibl':203C 'fals':143C 'file':135C,411C 'filesystem':406C 'filter':80B,467C 'fire':313C 'forward':480C,490C 'front':417C 'full':4A 'g':271C 'ghsa':17A,22A 'ghsa-c8w6-x74f-vmg3':16A,21A 'github':503C 'handl':322C,382C 'handler':159C,192C,281C 'impact':431C 'includ':95C 'indefinit':462C 'index':474C 'infrastructur':478C 'jubjub':189C,261C 'keep':70B,458C 'length':246C 'lightwalletd':38B,471C 'listunifiedreceiv':15A,56B,157C,425C,495C 'local':137C 'make':59B 'map':362C 'may':485C 'mine':40B,476C 'mining-pool':39B 'network':145C,287C 'node':5A,72B,218C,460C 'non':187C 'non-subgroup':186C 'none':184C,301C 'oper':469C 'order':243C 'own':366C 'packag':42B 'panic':63B,160C,211C,214C 'paramet':430C 'pass':52B,492C 'patch':351C 'path':346C,379C,491C 'paymentaddress':180C,294C 'pk':256C 'place':412C 'point':190C,263C 'pool':41B,477C 'port':150C,421C 'preimag':273C 'privat':502C 'process':62B,162C,219C,316C,440C 'produc':268C 'profil':209C 'propag':370C 'proper':368C 'proxi':415C 'random':303C 'reach':147C 'read':132C 'receiv':12A,170C 'reject':423C 'releas':208C 'remov':392C 'repeat':444C 'replac':359C 'report':497C 'request':69B,78B,436C,449C,465C 'requir':128C 'restart':75B,446C 'restrict':405C 'result':204C 'return':183C,300C,337C 'revers':414C 'robustfengbin':499C 'rout':350C,372C 'rpc':28A,46B,57B,107C,118C,149C,158C,223C,277C,354C,389C,420C,435C,481C 'rpc.listen':101C,393C 'run':90C 'sapl':11A,169C,178C,248C,286C,292C 'secur':504C 'server':108C,390C 'servic':8A 'set':100C,210C 'singl':67B,433C 'string':306C 'structur':164C,234C 'subgroup':188C,262C,309C 'submiss':506C 'summari':154C 'task':224C 'tcp':105C 'termin':215C,437C 'tri':284C,326C,376C 'trigger':152C,450C 'true':126C,401C 'typecod':242C 'typic':136C 'unifi':50B,166C,228C,238C,328C,378C 'untrust':428C 'upstream':468C 'use':195C,470C 'v4.4.1':96C 'valid':165C,177C,200C,231C,252C,260C,270C,349C 'via':9A,500C 'vmg3':20A,25A 'vulner':2A,344C 'whose':168C 'workaround':386C 'x74f':19A,24A 'z':14A,55B,156C,424C,494C 'zaino':473C 'zcash':43B,226C 'zebra':27A,45B,206C,276C,331C,353C 'zebra-chain':330C 'zebra-rpc':26A,44B,275C,352C 'zebrad':1A,29A,47B,61B,91C,357C,439C,484C 'zebrad.toml':99C,396C","nicknames":[],"mitigations":[],"who_affected":"Only nodes running zebrad with the RPC server enabled are exposed. With the default cookie auth, an attacker needs local read access to the .cookie file; with cookie auth disabled, any network client that can reach the RPC port can trigger the crash. Lightwalletd backends, Zaino indexers and mining pool setups that forward RPC calls to zebrad may be exposed if z_listunifiedreceivers is reachable through them.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":["zebrad","zebrarpc"],"ptokens":["rpc","zebra","zebrad"],"labels":["cargo","cwe20","cwe248","cwe617","cwe754","lightwalletd","medium","miningpool","package","zcash","zebrad","zebrarpc"],"campaign_type":null,"search_a":"'c8w6':18A,23A 'craft':10A 'denial':6A 'full':4A 'ghsa':17A,22A 'ghsa-c8w6-x74f-vmg3':16A,21A 'listunifiedreceiv':15A 'node':5A 'receiv':12A 'rpc':28A 'sapl':11A 'servic':8A 'via':9A 'vmg3':20A,25A 'vulner':2A 'x74f':19A,24A 'z':14A 'zebra':27A 'zebra-rpc':26A 'zebrad':1A,29A","search_b":"'-20':31B '-248':33B '-617':35B '-754':37B 'address':51B 'authent':68B 'call':58B 'craft':49B 'cwe':30B,32B,34B,36B 'exit':65B 'filter':80B 'keep':70B 'lightwalletd':38B 'listunifiedreceiv':56B 'make':59B 'mine':40B 'mining-pool':39B 'node':72B 'packag':42B 'panic':63B 'pass':52B 'pool':41B 'process':62B 'request':69B,78B 'restart':75B 'rpc':46B,57B 'singl':67B 'unifi':50B 'z':55B 'zcash':43B 'zebra':45B 'zebra-rpc':44B 'zebrad':47B,61B","search_c":"'-110':335C '/src/methods.rs':278C '/src/primitives/address.rs':333C '1':88C '2':97C '2893':279C '3':111C '32':304C '4.5.0':358C '43':172C,244C '8.0.0':355C '99':334C 'abort':212C,317C,453C 'access':138C,407C 'addr':102C,394C 'address':106C,167C,227C,239C,283C,429C 'advisori':505C 'affect':83C,86C 'allow':454C 'alreadi':197C,321C,381C 'attack':113C,130C,442C,456C 'auth':125C,142C,400C 'authent':115C,434C 'backend':472C 'bech32m':241C 'bypass':347C 'byte':173C,182C,245C,296C,299C,305C,341C 'call':193C,282C,426C,482C 'carri':171C 'case':384C 'chain':332C 'check':310C 'client':146C 'code':345C 'cooki':124C,134C,141C,399C,410C 'correct':324C,385C 'crate':320C 'credit':496C 'crypto':179C,293C 'cryptograph':176C 'd':257C,272C 'data':196C,288C 'decod':198C,230C 'default':122C,403C 'deleg':290C 'detail':225C 'disabl':387C 'diversifi':267C 'e':364C 'embed':255C 'enabl':110C,123C,140C,398C 'encod':229C 'endpoint':119C 'ensur':397C 'entir':217C 'envelop':235C 'err':338C,363C 'error':369C 'errorobject':365C 'exist':375C 'expect':194C,312C,360C 'expos':487C 'f4jumble':240C 'fail':175C,307C,342C 'fallibl':203C 'fals':143C 'file':135C,411C 'filesystem':406C 'filter':467C 'fire':313C 'forward':480C,490C 'front':417C 'g':271C 'github':503C 'handl':322C,382C 'handler':159C,192C,281C 'impact':431C 'includ':95C 'indefinit':462C 'index':474C 'infrastructur':478C 'jubjub':189C,261C 'keep':458C 'length':246C 'lightwalletd':471C 'listunifiedreceiv':157C,425C,495C 'local':137C 'map':362C 'may':485C 'mine':476C 'network':145C,287C 'node':218C,460C 'non':187C 'non-subgroup':186C 'none':184C,301C 'oper':469C 'order':243C 'own':366C 'panic':160C,211C,214C 'paramet':430C 'pass':492C 'patch':351C 'path':346C,379C,491C 'paymentaddress':180C,294C 'pk':256C 'place':412C 'point':190C,263C 'pool':477C 'port':150C,421C 'preimag':273C 'privat':502C 'process':162C,219C,316C,440C 'produc':268C 'profil':209C 'propag':370C 'proper':368C 'proxi':415C 'random':303C 'reach':147C 'read':132C 'receiv':170C 'reject':423C 'releas':208C 'remov':392C 'repeat':444C 'replac':359C 'report':497C 'request':436C,449C,465C 'requir':128C 'restart':446C 'restrict':405C 'result':204C 'return':183C,300C,337C 'revers':414C 'robustfengbin':499C 'rout':350C,372C 'rpc':107C,118C,149C,158C,223C,277C,354C,389C,420C,435C,481C 'rpc.listen':101C,393C 'run':90C 'sapl':169C,178C,248C,286C,292C 'secur':504C 'server':108C,390C 'set':100C,210C 'singl':433C 'string':306C 'structur':164C,234C 'subgroup':188C,262C,309C 'submiss':506C 'summari':154C 'task':224C 'tcp':105C 'termin':215C,437C 'tri':284C,326C,376C 'trigger':152C,450C 'true':126C,401C 'typecod':242C 'typic':136C 'unifi':166C,228C,238C,328C,378C 'untrust':428C 'upstream':468C 'use':195C,470C 'v4.4.1':96C 'valid':165C,177C,200C,231C,252C,260C,270C,349C 'via':500C 'vulner':344C 'whose':168C 'workaround':386C 'z':156C,424C,494C 'zaino':473C 'zcash':226C 'zebra':206C,276C,331C,353C 'zebra-chain':330C 'zebra-rpc':275C,352C 'zebrad':91C,357C,439C,484C 'zebrad.toml':99C,396C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-07-02T19:37:58+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvss_by":"GitHub","poc_count":0,"sources":[{"source":"ghsa","external_id":"GHSA-c8w6-x74f-vmg3","url":"https://github.com/advisories/GHSA-c8w6-x74f-vmg3","severity":"medium","published_at":"2026-07-02T19:37:58+00:00","modified_at":"2026-11-13T02:44:03+00:00","first_seen_at":"2026-11-13T02:48:40+00:00","fetched_at":"2026-11-13T02:48:40+00:00","note":null}],"documents":[{"id":142083,"url":"https://api.github.com/repos/ZcashFoundation/zebra/security-advisories/GHSA-c8w6-x74f-vmg3","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":142084,"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-c8w6-x74f-vmg3","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"}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}