CVE-2024-50354

CVE-2024-50354 is a medium-severity uncontrolled resource consumption vulnerability in github.com/consensys/gnark (go), affecting versions <= 0.11.0. It is fixed in 0.11.1.

Summary

Thanks @pventuzelo for reporting.

From the correspondence:

Hi,

We (Fuzzinglabs & Lambdaclass) found that during deserialization of certain files representing a VerifyingKey, an excessive memory allocation is happening consuming a lot of resources and even triggering a crash with the error fatal error: runtime: out of memory.

Please find the details below:

Vulnerability Details

  • Severity: Critical -> DoS
  • Affected Component: Deserialization

Environment

  • Compiler Version: go version go1.22.2 linux/amd64

  • Distro Version: Ubuntu 24.04.1 LTS

  • Additional Environment Details:

    • [github.com/consensys/gnark](http://github.com/consensys/gnark) v0.11.0
    • [github.com/consensys/gnark-crypto](http://github.com/consensys/gnark-crypto) v0.14.1-0.20240909142611-e6b99e74cec1

Steps to Reproduce

You can download the needed files here: https://drive.google.com/drive/folders/1KQ5I3vv4bUllvqbatGappwbAkIcR2NI_?usp=sharing

You have to run

go run gnark_poc.go

in a terminal.

Running the provided code will result in a memory crash or an extremely large memory allocation, which can be observed using the following command:

go tool pprof -web mem.pprof

Root Cause Analysis

The provided code loads a VerifyingKey from old.vk by calling the ReadFrom function. This function is implemented in backend/groth16/bn254/marshal.go within the gnark library.

The provided example uses the elliptic curve BN-254, so the code resides in the backend/groth16/bn254/ repertory. However, the same error exists in other repertories, such as backend/groth16/bls12-377/.

At line 207, a slice is allocated with a length of nbCommitments. This variable is directly extracted from the deserialized file, which, in our case, has a value of 2,327,186,600. This large value may be too big for some configurations, leading to memory allocations of approximately ±1 TB, as observed with pprof.

Detailed Behavior

go run gnark_poc.go

fatal error: runtime: out of memory

runtime stack:
runtime.throw({0x5fe946?, 0x2052ae?})
/usr/lib/go-1.22/src/runtime/panic.go:1023 +0x5c fp=0x7ffd65b321a0 sp=0x7ffd65b32170 pc=0x438a9c
runtime.sysMapOS(0xc000400000, 0x8ab6400000)
/usr/lib/go-1.22/src/runtime/mem_linux.go:167 +0x11b fp=0x7ffd65b321e0 sp=0x7ffd65b321a0 pc=0x418bbb
runtime.sysMap(0xc000400000, 0x8ab6400000, 0x7b19c8?)
/usr/lib/go-1.22/src/runtime/mem.go:155 +0x34 fp=0x7ffd65b32200 sp=0x7ffd65b321e0 pc=0x418634
runtime.(*mheap).grow(0x7a17c0, 0x455b066?)
/usr/lib/go-1.22/src/runtime/mheap.go:1534 +0x236 fp=0x7ffd65b32270 sp=0x7ffd65b32200 pc=0x42b176
runtime.(*mheap).allocSpan(0x7a17c0, 0x455b066, 0x0, 0x1)
/usr/lib/go-1.22/src/runtime/mheap.go:1246 +0x1b0 fp=0x7ffd65b32310 sp=0x7ffd65b32270 pc=0x42a850
runtime.(*mheap).alloc.func1()
/usr/lib/go-1.22/src/runtime/mheap.go:964 +0x5c fp=0x7ffd65b32358 sp=0x7ffd65b32310 pc=0x42a2fc
runtime.systemstack(0x46d79f)
/usr/lib/go-1.22/src/runtime/asm_amd64.s:509 +0x4a fp=0x7ffd65b32368 sp=0x7ffd65b32358 pc=0x46912a

goroutine 1 gp=0xc0000061c0 m=0 mp=0x798ca0 [running]:
runtime.systemstack_switch()
/usr/lib/go-1.22/src/runtime/asm_amd64.s:474 +0x8 fp=0xc000031b68 sp=0xc000031b58 pc=0x4690c8
runtime.(*mheap).alloc(0x5bc040?, 0xc00012bb08?, 0xa0?)
/usr/lib/go-1.22/src/runtime/mheap.go:958 +0x5b fp=0xc000031bb0 sp=0xc000031b68 pc=0x42a25b
runtime.(*mcache).allocLarge(0xc000126510?, 0x8ab60ca800, 0x1)
/usr/lib/go-1.22/src/runtime/mcache.go:234 +0x87 fp=0xc000031c00 sp=0xc000031bb0 pc=0x4176e7
runtime.mallocgc(0x8ab60ca800, 0x5d92a0, 0x1)
/usr/lib/go-1.22/src/runtime/malloc.go:1165 +0x597 fp=0xc000031c88 sp=0xc000031c00 pc=0x40ef97
runtime.makeslice(0xc00011c180?, 0x0?, 0x2?)
/usr/lib/go-1.22/src/runtime/slice.go:107 +0x49 fp=0xc000031cb0 sp=0xc000031c88 pc=0x4500c9
[github.com/consensys/gnark/backend/groth16/bn254.(*VerifyingKey).readFrom(0xc0001b7088](http://github.com/consensys/gnark/backend/groth16/bn254.(*VerifyingKey).readFrom(0xc0001b7088), {0x6598a0, 0xc00011dc50}, 0x0)
/home/raunan/go/pkg/mod/[github.com/!ronan!thoraval/[email protected]/backend/groth16/bn254/marshal.go:214](http://github.com/!ronan!thoraval/[email protected]/backend/groth16/bn254/marshal.go:214) +0x765 fp=0xc000031ea8 sp=0xc000031cb0 pc=0x59b205
[github.com/consensys/gnark/backend/groth16/bn254.(*VerifyingKey).ReadFrom(0x100469020](http://github.com/consensys/gnark/backend/groth16/bn254.(*VerifyingKey).ReadFrom(0x100469020)?, {0x6598a0?, 0xc00011dc50?})
/home/raunan/go/pkg/mod/[github.com/!ronan!thoraval/[email protected]/backend/groth16/bn254/marshal.go:166](http://github.com/!ronan!thoraval/[email protected]/backend/groth16/bn254/marshal.go:166) +0x1f fp=0xc000031ed8 sp=0xc000031ea8 pc=0x59aa5f
main.main()
/home/raunan/gnark_poc/gnark_poc/gnark_poc.go:19 +0xba fp=0xc000031f50 sp=0xc000031ed8 pc=0x5addda
runtime.main()
/usr/lib/go-1.22/src/runtime/proc.go:271 +0x29d fp=0xc000031fe0 sp=0xc000031f50 pc=0x43b55d
runtime.goexit({})
/usr/lib/go-1.22/src/runtime/asm_amd64.s:1695 +0x1 fp=0xc000031fe8 sp=0xc000031fe0 pc=0x46b0e1

goroutine 2 gp=0xc000006c40 m=nil [force gc (idle)]:
runtime.gopark(0x0?, 0x0?, 0x0?, 0x0?, 0x0?)
/usr/lib/go-1.22/src/runtime/proc.go:402 +0xce fp=0xc000074fa8 sp=0xc000074f88 pc=0x43b98e
runtime.goparkunlock(...)
/usr/lib/go-1.22/src/runtime/proc.go:408
runtime.forcegchelper()
/usr/lib/go-1.22/src/runtime/proc.go:326 +0xb3 fp=0xc000074fe0 sp=0xc000074fa8 pc=0x43b813
runtime.goexit({})
/usr/lib/go-1.22/src/runtime/asm_amd64.s:1695 +0x1 fp=0xc000074fe8 sp=0xc000074fe0 pc=0x46b0e1
created by runtime.init.6 in goroutine 1
/usr/lib/go-1.22/src/runtime/proc.go:314 +0x1a

goroutine 3 gp=0xc000007180 m=nil [GC sweep wait]:
runtime.gopark(0x0?, 0x0?, 0x0?, 0x0?, 0x0?)
/usr/lib/go-1.22/src/runtime/proc.go:402 +0xce fp=0xc000075780 sp=0xc000075760 pc=0x43b98e
runtime.goparkunlock(...)
/usr/lib/go-1.22/src/runtime/proc.go:408
runtime.bgsweep(0xc0000240e0)
/usr/lib/go-1.22/src/runtime/mgcsweep.go:278 +0x94 fp=0xc0000757c8 sp=0xc000075780 pc=0x426cf4
runtime.gcenable.gowrap1()
/usr/lib/go-1.22/src/runtime/mgc.go:203 +0x25 fp=0xc0000757e0 sp=0xc0000757c8 pc=0x41b845
runtime.goexit({})
/usr/lib/go-1.22/src/runtime/asm_amd64.s:1695 +0x1 fp=0xc0000757e8 sp=0xc0000757e0 pc=0x46b0e1
created by runtime.gcenable in goroutine 1
/usr/lib/go-1.22/src/runtime/mgc.go:203 +0x66

goroutine 4 gp=0xc000007340 m=nil [GC scavenge wait]:
runtime.gopark(0xc0000240e0?, 0x657100?, 0x1?, 0x0?, 0xc000007340?)
/usr/lib/go-1.22/src/runtime/proc.go:402 +0xce fp=0xc000075f78 sp=0xc000075f58 pc=0x43b98e
runtime.goparkunlock(...)
/usr/lib/go-1.22/src/runtime/proc.go:408
runtime.(*scavengerState).park(0x797520)
/usr/lib/go-1.22/src/runtime/mgcscavenge.go:425 +0x49 fp=0xc000075fa8 sp=0xc000075f78 pc=0x4246e9
runtime.bgscavenge(0xc0000240e0)
/usr/lib/go-1.22/src/runtime/mgcscavenge.go:653 +0x3c fp=0xc000075fc8 sp=0xc000075fa8 pc=0x424c7c
runtime.gcenable.gowrap2()
/usr/lib/go-1.22/src/runtime/mgc.go:204 +0x25 fp=0xc000075fe0 sp=0xc000075fc8 pc=0x41b7e5
runtime.goexit({})
/usr/lib/go-1.22/src/runtime/asm_amd64.s:1695 +0x1 fp=0xc000075fe8 sp=0xc000075fe0 pc=0x46b0e1
created by runtime.gcenable in goroutine 1
/usr/lib/go-1.22/src/runtime/mgc.go:204 +0xa5

goroutine 18 gp=0xc000102700 m=nil [finalizer wait]:
runtime.gopark(0xc000074648?, 0x40f445?, 0xa8?, 0x1?, 0xc0000061c0?)
/usr/lib/go-1.22/src/runtime/proc.go:402 +0xce fp=0xc000074620 sp=0xc000074600 pc=0x43b98e
runtime.runfinq()
/usr/lib/go-1.22/src/runtime/mfinal.go:194 +0x107 fp=0xc0000747e0 sp=0xc000074620 pc=0x41a887
runtime.goexit({})
/usr/lib/go-1.22/src/runtime/asm_amd64.s:1695 +0x1 fp=0xc0000747e8 sp=0xc0000747e0 pc=0x46b0e1
created by runtime.createfing in goroutine 1
/usr/lib/go-1.22/src/runtime/mfinal.go:164 +0x3d
exit status 2

Appendices

This problem can also happen with ProvingKey.

Workarounds

There are no convenient work-arounds currently. The best approach currently is to run key verification as a separate service which halts the verification pipeline in case of OOM when verification keys come from untrusted sources.

Impact

Prover and verifier denial of service in case of maliciously crafted inputs (public key, verification key).

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2024-50354 has a CVSS score of 5.5 (Medium). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.11.1); upgrading removes the vulnerable code path.

Affected versions

github.com/consensys/gnark (<= 0.11.0)

Security releases

github.com/consensys/gnark → 0.11.1 (go)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

See it in your environment

Remediation advice

The issue is patched in https://github.com/Consensys/gnark/pull/1307. It was merged to gnark master at https://github.com/Consensys/gnark/commit/47ae846339add2bdf9983e499342bfdfe195191d. The fix will be incorporated in the next minor release of gnark (v0.11.1).

Frequently Asked Questions

  1. What is CVE-2024-50354? CVE-2024-50354 is a medium-severity uncontrolled resource consumption vulnerability in github.com/consensys/gnark (go), affecting versions <= 0.11.0. It is fixed in 0.11.1. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
  2. How severe is CVE-2024-50354? CVE-2024-50354 has a CVSS score of 5.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
  3. Which versions of github.com/consensys/gnark are affected by CVE-2024-50354? github.com/consensys/gnark (go) versions <= 0.11.0 is affected.
  4. Is there a fix for CVE-2024-50354? Yes. CVE-2024-50354 is fixed in 0.11.1. Upgrade to this version or later.
  5. Is CVE-2024-50354 exploitable, and should I be worried? Whether CVE-2024-50354 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
  6. What actually determines whether CVE-2024-50354 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
  7. How do I fix CVE-2024-50354? Upgrade github.com/consensys/gnark to 0.11.1 or later.

Other vulnerabilities in github.com/consensys/gnark

CVE-2025-57801CVE-2024-50354CVE-2024-45039CVE-2024-45040CVE-2023-44378

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