Wallet: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2023-33241 is a critical-severity improper neutralization of special elements in output used by a downstream component vulnerability in Wallet from GG TSS Implementations, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Wallet versions: 18; 20. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.18% chance of exploitation within 30 days, higher than 68% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Wallet you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| GG TSS Implementations | Wallet | 18; 20 | Not stated |
| Gg18 Project | Gg18 | Not specified in the record | Not stated |
| Gg20 Project | Gg20 | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.6 | Critical | CNA (halborn.com) |
| CVSS 3.1 | 9.1 | Critical | NVD |
Official description
Crypto wallets implementing the GG18 or GG20 TSS protocol might allow an attacker to extract a full ECDSA private key by injecting a malicious pallier key and cheating in the range proof. Depending on the Beta parameters chosen in the protocol implementation, the attack might require 16 signatures or more fully exfiltrate the other parties' private key shares.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How developers prevent this class of flaw
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- fireblocks.com/blog/gg18-and-gg20-paillier-key-vulnerability-technical-report/Third Party Advisory
Technical write-ups (may include proof of concept)
- eprint.iacr.org/2019/114.pdfExploit, Third Party Advisory
- eprint.iacr.org/2020/540.pdfExploit, Third Party Advisory
- github.com/fireblocks-labs/mpc-ecdsa-attacks-23Exploit
- github.com/fireblocks-labs/safeheron-gg20-exploit-pocExploit
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 8.1 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
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