019bb004-7b0f-73a8-8090-aaa6e87c7325
Open this run to answer one question: is this real attacker-relevant behavior with real impact, or just normal contract plumbing?
| ID | Type | Status | Attempts | Heartbeat |
|---|---|---|---|---|
| 39367 | artifact.fetch | complete | 1 / 3 | 3 months ago |
| 39368 | proxy.resolve | complete | 1 / 3 | 3 months ago |
| 39369 | tool.cast_disasm | complete | 1 / 3 | 3 months ago |
| 39370 | analysis.bundle | complete | 1 / 3 | 3 months ago |
| 39371 | capability.graph | complete | 1 / 3 | 3 months ago |
| 39372 | detector.run | complete | 1 / 3 | 3 months ago |
| 39373 | validation.fork | complete | 1 / 3 | 3 months ago |
| 39484 | report.consolidate | complete | 1 / 6 | 3 months ago |
{
"status": "not_proxy"
}
No slither job recorded yet.
{"no_findings":false,"summary":"Bytecode appears to implement a proxy-like fallback that DELEGATECALLs to an address stored in slot0, with a public selector that can write slot0. This creates upgradeability and storage-collision risks if slot0 can be modified or if delegated logic writes to slot0.","findings":[{"severity":"high","category":"upgradeability","title":"Computed DELEGATECALL target controlled by storage slot0","exploit_scenario":"The fallback path performs a DELEGATECALL to the address loaded from storage slot0. If an attacker can modify slot0 (e.g., through the callable selector 0x10e88892 if they satisfy its guard, or by exploiting storage collision in delegated logic), they can redirect the proxy to malicious code and execute arbitrary state changes or drain funds in the proxy’s storage context. Selector inference is best-effort, so the exact upgrade entrypoint is uncertain, but the slot write is present.","recommendation":"Use a dedicated, non-colliding implementation slot (EIP-1967), and gate upgrades behind explicit, well-audited access control. If upgrades are not intended, make the implementation immutable. Emit upgrade events and validate that new implementations are contracts.","evidence":"DELEGATECALL at pc 125 with computed target; SLOAD from slot0 at pc 59 feeds the target; SSTORE to slot0 at pc 279 is reachable via selector 0x10e88892.","locations":["pc:0x7d","pc:0x3b","pc:0x117","selector:0x10e88892"]},{"severity":"medium","category":"upgradeability","title":"Implementation stored in slot0 risks storage collision with delegated logic","exploit_scenario":"Slot0 is used as the implementation address. Any delegated implementation that also uses slot0 for its own state (common for variables like `owner`) can inadvertently overwrite the proxy’s implementation pointer. A buggy or malicious function writing to slot0 could brick the proxy or switch it to attacker-controlled code. This is a known risk of non-unstructured proxy storage layouts.","recommendation":"Move the implementation pointer to an unstructured slot (e.g., EIP-1967) and ensure implementations never write to that slot. If migration is impossible, audit delegated implementations to ensure slot0 is never written.","evidence":"Slot0 is read for the delegatecall target (pc 59) and written via SSTORE (pc 279). No evidence of EIP-1967 or separate admin/implementation slots is present in the bytecode artifact.","locations":["pc:0x3b","pc:0x117"]}]}
OpenAI Codex v0.77.0 (research preview)
--------
workdir: /tmp/codex-kdxd8geu
model: gpt-5.2-codex
provider: openai
approval: never
sandbox: read-only
reasoning effort: high
reasoning summaries: auto
session id: 019bb028-5cd7-7612-9339-87b94f4ab990
--------
user
You are a security auditor. You ONLY have runtime bytecode + analysis artifacts.
You MUST read `BYTECODE_BUNDLE.json` before concluding; it contains the bytecode summary,
evidence bundle, callsites, storage slots, and detector findings.
Special cases when reasoning from bytecode (be explicit about uncertainty):
- Selector inference is best-effort; missing selectors are common.
- Fallback/receive paths may be the only entrypoints.
- CALL vs DELEGATECALL semantics differ; DELEGATECALL executes in caller storage.
- Proxy patterns (EIP-1967, minimal proxies, beacon) change which storage is authoritative.
- Storage slots are raw; mappings/arrays appear via keccak patterns, names are unknown.
- Guard detection is heuristic; absence of guards does NOT mean unguarded.
- Returndata checking is unknown unless explicitly shown in evidence.
- Precompiles (0x1..0x9) and common ERC20 transfer selectors may appear; do not over-claim.
Output MUST be valid JSON matching the provided schema.
- If you find nothing meaningful: set no_findings=true and findings=[].
- Otherwise: set no_findings=false and include findings with severity/category/title.
- Locations can be pc references like "pc:0x123" or selectors like "selector:0xa9059cbb".
Focus on: reentrancy, access control, upgradeability/proxy issues, signature validation,
accounting/invariant breaks, dangerous delegatecall, and untrusted external calls.
Be conservative: if evidence is weak, mark severity low/medium and explain why.
mcp startup: no servers
thinking
**Reading BYTECODE_BUNDLE.json**
exec
/bin/bash -lc ls in /tmp/codex-kdxd8geu succeeded in 8ms:
BYTECODE_BUNDLE.json
codex-output-schema.json
exec
/bin/bash -lc 'cat BYTECODE_BUNDLE.json' in /tmp/codex-kdxd8geu succeeded in 5ms:
{
"analysis_artifact": {
"address": "0x05ff2b0db69458a0750badebc4f9e13add608c7f",
"artifact_hash": "0xc89078c262b1e5aa2efbbe43fed1eeffdd3648a3269454f8624cb173dcec74c4",
"artifact_json": {
"auth": {
"guards": [
{
"pc": 247,
"type": "msg_sender_eq_const",
"value": "0xffffffffffffffffffffffffffffffffffffffff"
}
]
},
"basic_blocks": [
{
"end_pc": 12,
"hash": "0xe5d68b875c5ae17924c16c7139df51eac5236b76b6df0fa11e70a174e44416fe",
"opcodes": [
"PUSH1",
thinking
**Summarizing proxy contract analysis**
I’m unpacking a proxy contract using storage slot0 both as implementation pointer and owner, with a fallback delegatecall to that slot0 address. It uses a guarded upgrade pattern where only the current implementation can change the implementation, which is unusual and poses risks like storage collision and upgrade by compromised implementation. The proxy doesn’t follow EIP-1967 standards, increasing vulnerability. I’m carefully evaluating guards and bytecode flow to capture these nuances for a JSON output summarizing the key security and design findings.
thinking
**Detailing upgradeability and storage risks**
I'm breaking down two main findings: a high-severity issue where delegatecall uses a storage slot as a dynamically controlled target, risking arbitrary code execution if that slot is modified; and a medium-severity risk from storing the implementation address in slot0 without EIP-1967 separation, risking storage collision where implementation writes could alter the proxy’s behavior or brick it. I’m preparing a JSON output with these findings, their evidence, and recommendations for safer proxy patterns.
codex
{"no_findings":false,"summary":"Bytecode appears to implement a proxy-like fallback that DELEGATECALLs to an address stored in slot0, with a public selector that can write slot0. This creates upgradeability and storage-collision risks if slot0 can be modified or if delegated logic writes to slot0.","findings":[{"severity":"high","category":"upgradeability","title":"Computed DELEGATECALL target controlled by storage slot0","exploit_scenario":"The fallback path performs a DELEGATECALL to the address loaded from storage slot0. If an attacker can modify slot0 (e.g., through the callable selector 0x10e88892 if they satisfy its guard, or by exploiting storage collision in delegated logic), they can redirect the proxy to malicious code and execute arbitrary state changes or drain funds in the proxy’s storage context. Selector inference is best-effort, so the exact upgrade entrypoint is uncertain, but the slot write is present.","recommendation":"Use a dedicated, non-colliding implementation slot (EIP-1967), and gate upgrades behind explicit, well-audited access control. If upgrades are not intended, make the implementation immutable. Emit upgrade events and validate that new implementations are contracts.","evidence":"DELEGATECALL at pc 125 with computed target; SLOAD from slot0 at pc 59 feeds the target; SSTORE to slot0 at pc 279 is reachable via selector 0x10e88892.","locations":["pc:0x7d","pc:0x3b","pc:0x117","selector:0x10e88892"]},{"severity":"medium","category":"upgradeability","title":"Implementation stored in slot0 risks storage collision with delegated logic","exploit_scenario":"Slot0 is used as the implementation address. Any delegated implementation that also uses slot0 for its own state (common for variables like `owner`) can inadvertently overwrite the proxy’s implementation pointer. A buggy or malicious function writing to slot0 could brick the proxy or switch it to attacker-controlled code. This is a known risk of non-unstructured proxy storage layouts.","recommendation":"Move the implementation pointer to an unstructured slot (e.g., EIP-1967) and ensure implementations never write to that slot. If migration is impossible, audit delegated implementations to ensure slot0 is never written.","evidence":"Slot0 is read for the delegatecall target (pc 59) and written via SSTORE (pc 279). No evidence of EIP-1967 or separate admin/implementation slots is present in the bytecode artifact.","locations":["pc:0x3b","pc:0x117"]}]}
tokens used
27,655
{
"codex": {
"ran_at": "2026-01-12T03:05:15.484651+00:00",
"returncode": 0
},
"project": {
"mode": "bytecode",
"bytecode_length": 1090,
"bytecode_truncated": false,
"capability_graph_present": true,
"analysis_artifact_present": true
},
"summary": "Bytecode appears to implement a proxy-like fallback that DELEGATECALLs to an address stored in slot0, with a public selector that can write slot0. This creates upgradeability and storage-collision risks if slot0 can be modified or if delegated logic writes to slot0.",
"raw_final": {
"summary": "Bytecode appears to implement a proxy-like fallback that DELEGATECALLs to an address stored in slot0, with a public selector that can write slot0. This creates upgradeability and storage-collision risks if slot0 can be modified or if delegated logic writes to slot0.",
"findings": [
{
"title": "Computed DELEGATECALL target controlled by storage slot0",
"category": "upgradeability",
"evidence": "DELEGATECALL at pc 125 with computed target; SLOAD from slot0 at pc 59 feeds the target; SSTORE to slot0 at pc 279 is reachable via selector 0x10e88892.",
"severity": "high",
"locations": [
"pc:0x7d",
"pc:0x3b",
"pc:0x117",
"selector:0x10e88892"
],
"recommendation": "Use a dedicated, non-colliding implementation slot (EIP-1967), and gate upgrades behind explicit, well-audited access control. If upgrades are not intended, make the implementation immutable. Emit upgrade events and validate that new implementations are contracts.",
"exploit_scenario": "The fallback path performs a DELEGATECALL to the address loaded from storage slot0. If an attacker can modify slot0 (e.g., through the callable selector 0x10e88892 if they satisfy its guard, or by exploiting storage collision in delegated logic), they can redirect the proxy to malicious code and execute arbitrary state changes or drain funds in the proxy\u2019s storage context. Selector inference is best-effort, so the exact upgrade entrypoint is uncertain, but the slot write is present."
},
{
"title": "Implementation stored in slot0 risks storage collision with delegated logic",
"category": "upgradeability",
"evidence": "Slot0 is read for the delegatecall target (pc 59) and written via SSTORE (pc 279). No evidence of EIP-1967 or separate admin/implementation slots is present in the bytecode artifact.",
"severity": "medium",
"locations": [
"pc:0x3b",
"pc:0x117"
],
"recommendation": "Move the implementation pointer to an unstructured slot (e.g., EIP-1967) and ensure implementations never write to that slot. If migration is impossible, audit delegated implementations to ensure slot0 is never written.",
"exploit_scenario": "Slot0 is used as the implementation address. Any delegated implementation that also uses slot0 for its own state (common for variables like `owner`) can inadvertently overwrite the proxy\u2019s implementation pointer. A buggy or malicious function writing to slot0 could brick the proxy or switch it to attacker-controlled code. This is a known risk of non-unstructured proxy storage layouts."
}
],
"no_findings": false
},
"no_findings": false,
"schema_version": 1
}
00000000: PUSH1 0x80 00000002: PUSH1 0x40 00000004: MSTORE 00000005: PUSH1 0x04 00000007: CALLDATASIZE 00000008: LT 00000009: PUSH2 0x0022 0000000c: JUMPI 0000000d: PUSH1 0x00 0000000f: CALLDATALOAD 00000010: PUSH1 0xe0 00000012: SHR 00000013: DUP1 00000014: PUSH4 0x10e88892 00000019: EQ 0000001a: PUSH2 0x0094 0000001d: JUMPI 0000001e: PUSH2 0x0023 00000021: JUMP 00000022: JUMPDEST 00000023: JUMPDEST 00000024: PUSH20 0xffffffffffffffffffffffffffffffffffffffff 00000039: PUSH1 0x00 0000003b: SLOAD 0000003c: AND 0000003d: PUSH32 0xa619486e00000000000000000000000000000000000000000000000000000000 0000005e: PUSH1 0x00 00000060: CALLDATALOAD 00000061: SUB 00000062: PUSH2 0x006f 00000065: JUMPI 00000066: DUP1 00000067: PUSH1 0x00 00000069: MSTORE 0000006a: PUSH1 0x20 0000006c: PUSH1 0x00 0000006e: RETURN 0000006f: JUMPDEST 00000070: CALLDATASIZE 00000071: PUSH1 0x00 00000073: DUP1 00000074: CALLDATACOPY 00000075: PUSH1 0x00 00000077: DUP1 00000078: CALLDATASIZE 00000079: PUSH1 0x00 0000007b: DUP5 0000007c: GAS 0000007d: DELEGATECALL 0000007e: RETURNDATASIZE 0000007f: PUSH1 0x00 00000081: DUP1 00000082: RETURNDATACOPY 00000083: PUSH1 0x00 00000085: DUP2 00000086: SUB 00000087: PUSH2 0x008f 0000008a: JUMPI 0000008b: RETURNDATASIZE 0000008c: PUSH1 0x00 0000008e: REVERT 0000008f: JUMPDEST 00000090: RETURNDATASIZE 00000091: PUSH1 0x00 00000093: RETURN 00000094: JUMPDEST 00000095: CALLVALUE 00000096: DUP1 00000097: ISZERO 00000098: PUSH2 0x00a0 0000009b: JUMPI 0000009c: PUSH1 0x00 0000009e: DUP1 0000009f: REVERT 000000a0: JUMPDEST 000000a1: POP 000000a2: PUSH2 0x00bb 000000a5: PUSH1 0x04 000000a7: DUP1 000000a8: CALLDATASIZE 000000a9: SUB 000000aa: DUP2 000000ab: ADD 000000ac: SWAP1 000000ad: PUSH2 0x00b6 000000b0: SWAP2 000000b1: SWAP1 000000b2: PUSH2 0x01bd 000000b5: JUMP 000000b6: JUMPDEST 000000b7: PUSH2 0x00bd 000000ba: JUMP 000000bb: JUMPDEST 000000bc: STOP 000000bd: JUMPDEST 000000be: PUSH1 0x01 000000c0: PUSH1 0x00 000000c2: SWAP1 000000c3: SLOAD 000000c4: SWAP1 000000c5: PUSH2 0x0100 000000c8: EXP 000000c9: SWAP1 000000ca: DIV 000000cb: PUSH20 0xffffffffffffffffffffffffffffffffffffffff 000000e0: AND 000000e1: PUSH20 0xffffffffffffffffffffffffffffffffffffffff 000000f6: AND 000000f7: CALLER 000000f8: PUSH20 0xffffffffffffffffffffffffffffffffffffffff 0000010d: AND 0000010e: EQ 0000010f: PUSH2 0x0117 00000112: JUMPI 00000113: PUSH1 0x00 00000115: DUP1 00000116: REVERT 00000117: JUMPDEST 00000118: DUP1 00000119: PUSH1 0x00 0000011b: DUP1 0000011c: PUSH2 0x0100 0000011f: EXP 00000120: DUP2 00000121: SLOAD 00000122: DUP2 00000123: PUSH20 0xffffffffffffffffffffffffffffffffffffffff 00000138: MUL 00000139: NOT 0000013a: AND 0000013b: SWAP1 0000013c: DUP4 0000013d: PUSH20 0xffffffffffffffffffffffffffffffffffffffff 00000152: AND 00000153: MUL 00000154: OR 00000155: SWAP1 00000156: SSTORE 00000157: POP 00000158: POP 00000159: JUMP 0000015a: JUMPDEST 0000015b: PUSH1 0x00 0000015d: DUP1 0000015e: REVERT 0000015f: JUMPDEST 00000160: PUSH1 0x00 00000162: PUSH20 0xffffffffffffffffffffffffffffffffffffffff 00000177: DUP3 00000178: AND 00000179: SWAP1 0000017a: POP 0000017b: SWAP2 0000017c: SWAP1 0000017d: POP 0000017e: JUMP 0000017f: JUMPDEST 00000180: PUSH1 0x00 00000182: PUSH2 0x018a 00000185: DUP3 00000186: PUSH2 0x015f 00000189: JUMP 0000018a: JUMPDEST 0000018b: SWAP1 0000018c: POP 0000018d: SWAP2 0000018e: SWAP1 0000018f: POP 00000190: JUMP 00000191: JUMPDEST 00000192: PUSH2 0x019a 00000195: DUP2 00000196: PUSH2 0x017f 00000199: JUMP 0000019a: JUMPDEST 0000019b: DUP2 0000019c: EQ 0000019d: PUSH2 0x01a5 000001a0: JUMPI 000001a1: PUSH1 0x00 000001a3: DUP1 000001a4: REVERT 000001a5: JUMPDEST 000001a6: POP 000001a7: JUMP 000001a8: JUMPDEST 000001a9: PUSH1 0x00 000001ab: DUP2 000001ac: CALLDATALOAD 000001ad: SWAP1 000001ae: POP 000001af: PUSH2 0x01b7 000001b2: DUP2 000001b3: PUSH2 0x0191 000001b6: JUMP 000001b7: JUMPDEST 000001b8: SWAP3 000001b9: SWAP2 000001ba: POP 000001bb: POP 000001bc: JUMP 000001bd: JUMPDEST 000001be: PUSH1 0x00 000001c0: PUSH1 0x20 000001c2: DUP3 000001c3: DUP5 000001c4: SUB 000001c5: SLT 000001c6: ISZERO 000001c7: PUSH2 0x01d3 000001ca: JUMPI 000001cb: PUSH2 0x01d2 000001ce: PUSH2 0x015a 000001d1: JUMP 000001d2: JUMPDEST 000001d3: JUMPDEST 000001d4: PUSH1 0x00 000001d6: PUSH2 0x01e1 000001d9: DUP5 000001da: DUP3 000001db: DUP6 000001dc: ADD 000001dd: PUSH2 0x01a8 000001e0: JUMP 000001e1: JUMPDEST 000001e2: SWAP2 000001e3: POP 000001e4: POP 000001e5: SWAP3 000001e6: SWAP2 000001e7: POP 000001e8: POP 000001e9: JUMP 000001ea: INVALID 000001eb: LOG2 000001ec: PUSH5 0x6970667358 000001f2: UNKNOWN(0x22) 000001f3: SLT 000001f4: KECCAK256 000001f5: EQ 000001f6: BLOCKHASH 000001f7: PUSH12 0x0352b962330a82d8b75d095a 00000204: UNKNOWN(0x1F) 00000205: DIFFICULTY 00000206: UNKNOWN(0xA5) 00000207: ADDRESS 00000208: BALANCE 00000209: DUP4 0000020a: UNKNOWN(0xFB) 0000020b: DELEGATECALL 0000020c: PUSH6 0xcbccaf6db0a1 00000213: RETURN 00000214: UNKNOWN(0x27) 00000215: PUSH5 0x736f6c6343 0000021b: STOP 0000021c: ADDMOD 0000021d: GT 0000021e: STOP 0000021f: CALLER
| Severity | Category | Tool | Title | Confidence | Validated | Confirmed | Details |
|---|---|---|---|---|---|---|---|
| high | upgradeability | detector | Untrusted DELEGATECALL target reachable | 55 | no | no |
viewtrace_id: 0xfad8c8414bd77406deeb3a633715d48657934dd5fc1d297245e6d63bc26de5b4
validation_json{
"sink": "DELEGATECALL",
"errors": 0,
"status": "unknown",
"attempts": 12,
"trace_id": "0xfad8c8414bd77406deeb3a633715d48657934dd5fc1d297245e6d63bc26de5b4",
"confirmed": false,
"trace_mode": "callTracer",
"call_targets": null,
"matched_probe": null,
"target_varies": null,
"classification": "no_sink"
}
witness_json{
"notes": "heuristic witness; entrypoints are best-effort selectors with zeroed calldata",
"constraints": [],
"entrypoints": [
{
"calldata": "0x10e88892",
"selector": "0x10e88892",
"calldata_variants": [
"0x10e88892",
"0x10e888920000000000000000000000000000000000000000000000000000000000000000"
]
}
]
}
evidence_json{
"examples": [
{
"pc": 125,
"opcode": "DELEGATECALL",
"returndata_checked": null,
"value_expression_category": "n/a",
"target_expression_category": "computed"
},
{
"pc": 523,
"opcode": "DELEGATECALL",
"returndata_checked": null,
"value_expression_category": "n/a",
"target_expression_category": "computed"
}
],
"guards_detected": [
{
"pc": 247,
"type": "msg_sender_eq_const",
"value": "0xffffffffffffffffffffffffffffffffffffffff"
}
],
"delegatecall_count": 2,
"untrusted_delegatecall_count": 2
}
|
| high | upgradeability | codex | Computed DELEGATECALL target controlled by storage slot0 | 85 | no | — |
viewevidence_json{
"evidence": "DELEGATECALL at pc 125 with computed target; SLOAD from slot0 at pc 59 feeds the target; SSTORE to slot0 at pc 279 is reachable via selector 0x10e88892.",
"locations": [
"pc:0x7d",
"pc:0x3b",
"pc:0x117",
"selector:0x10e88892"
],
"recommendation": "Use a dedicated, non-colliding implementation slot (EIP-1967), and gate upgrades behind explicit, well-audited access control. If upgrades are not intended, make the implementation immutable. Emit upgrade events and validate that new implementations are contracts.",
"exploit_scenario": "The fallback path performs a DELEGATECALL to the address loaded from storage slot0. If an attacker can modify slot0 (e.g., through the callable selector 0x10e88892 if they satisfy its guard, or by exploiting storage collision in delegated logic), they can redirect the proxy to malicious code and execute arbitrary state changes or drain funds in the proxy\u2019s storage context. Selector inference is best-effort, so the exact upgrade entrypoint is uncertain, but the slot write is present."
}
|
| medium | upgradeability | cast | DELEGATECALL present | 80 | no | — |
viewevidence_json{
"notes": "delegatecall enables execution in caller context; common in proxies/upgradeable patterns",
"delegatecall_count": 2
}
|
| medium | upgradeability | codex | Implementation stored in slot0 risks storage collision with delegated logic | 75 | no | — |
viewevidence_json{
"evidence": "Slot0 is read for the delegatecall target (pc 59) and written via SSTORE (pc 279). No evidence of EIP-1967 or separate admin/implementation slots is present in the bytecode artifact.",
"locations": [
"pc:0x3b",
"pc:0x117"
],
"recommendation": "Move the implementation pointer to an unstructured slot (e.g., EIP-1967) and ensure implementations never write to that slot. If migration is impossible, audit delegated implementations to ensure slot0 is never written.",
"exploit_scenario": "Slot0 is used as the implementation address. Any delegated implementation that also uses slot0 for its own state (common for variables like `owner`) can inadvertently overwrite the proxy\u2019s implementation pointer. A buggy or malicious function writing to slot0 could brick the proxy or switch it to attacker-controlled code. This is a known risk of non-unstructured proxy storage layouts."
}
|