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nano-id reduced entropy due to inadequate character set usage

Critical severity GitHub Reviewed Published Jun 4, 2024 to the GitHub Advisory Database • Updated Jun 4, 2024

Package

cargo nano-id (Rust)

Affected versions

< 0.4.0

Patched versions

0.4.0

Description

Description

Affected versions of the nano-id crate incorrectly generated IDs using a reduced character set in the nano_id::base62 and nano_id::base58 functions. Specifically, the base62 function used a character set of 32 symbols instead of the intended 62 symbols, and the base58 function used a character set of 16 symbols instead of the intended 58 symbols. Additionally, the nano_id::gen macro is also affected when a custom character set that is not a power of 2 in size is specified.

It should be noted that nano_id::base64 is not affected by this vulnerability.

Impact

This can result in a significant reduction in entropy, making the generated IDs predictable and vulnerable to brute-force attacks when the IDs are used in security-sensitive contexts such as session tokens or unique identifiers.

Patches

The flaws were corrected in commit a9022772b2f1ce38929b5b81eccc670ac9d3ab23 by updating the the nano_id::gen macro to use all specified characters correctly.

PoC

use std::collections::BTreeSet;

fn main() {
    test_base58();
    test_base62();
}

fn test_base58() {
    let mut produced_symbols = BTreeSet::new();

    for _ in 0..100_000 {
id = "RUSTSEC-2024-0343"
        for c in id.chars() {
            produced_symbols.insert(c);
        }
    }

    println!(
        "{} symbols generated from nano_id::base58",
        produced_symbols.len()
    );
}

fn test_base62() {
    let mut produced_symbols = BTreeSet::new();

    for _ in 0..100_000 {
id = "RUSTSEC-2024-0343"
        for c in id.chars() {
            produced_symbols.insert(c);
        }
    }

    println!(
        "{} symbols generated from nano_id::base62",
        produced_symbols.len()
    );
}

References

Published to the GitHub Advisory Database Jun 4, 2024
Reviewed Jun 4, 2024
Last updated Jun 4, 2024

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L

Weaknesses

CVE ID

No known CVE

GHSA ID

GHSA-2hfw-w739-p7x5

Source code

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