vulnerability / NVI-00013794 / Revision 1
joi: object().rename() with a template target can set the validated object's prototype
GitHub lists this reviewed advisory for joi, joi. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
3.7 low
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
joi
source listed>= 16.0.0, < 17.13.5
### Impact Applications are affected only if a schema renames keys with a regular-expression source and a `Joi.expression()` / `Joi.x()` target that interpolates the pattern's own match data, combined with `{ multiple: true }`, for example `.rename(/^x-(.+)$/, Joi.x('{#1}'), { multiple: true })`. Because the target is rendered from the matched input key, an attacker who controls input keys can send `x-__proto__` with an object value and make the rename target render as `__proto__`, which sets the prototype of the object joi returns instead of creating a key on it. The global `Object.prototype` is not modified, so the effect is confined to the object returned by that one `validate()` call. Schemas using a static string rename target are not affected, and neither are schemas left on the default `{ multiple: false }`. ### Patches Versions 17.13.5 and 18.2.4 have been released to address the issue. ### Workarounds 1. Replace the template rename target with a static string target. 2. Keep the template but make the capture unable to produce `__proto__`, using a negative lookahead: `.rename(/^x-(?!__proto__$)(.+)$/, Joi.x('{#1}'), { multiple: true })` 3. Drop { multiple: true } from
joi
source listed>= 18.0.0, < 18.2.4
### Impact Applications are affected only if a schema renames keys with a regular-expression source and a `Joi.expression()` / `Joi.x()` target that interpolates the pattern's own match data, combined with `{ multiple: true }`, for example `.rename(/^x-(.+)$/, Joi.x('{#1}'), { multiple: true })`. Because the target is rendered from the matched input key, an attacker who controls input keys can send `x-__proto__` with an object value and make the rename target render as `__proto__`, which sets the prototype of the object joi returns instead of creating a key on it. The global `Object.prototype` is not modified, so the effect is confined to the object returned by that one `validate()` call. Schemas using a static string rename target are not affected, and neither are schemas left on the default `{ multiple: false }`. ### Patches Versions 17.13.5 and 18.2.4 have been released to address the issue. ### Workarounds 1. Replace the template rename target with a static string target. 2. Keep the template but make the capture unable to produce `__proto__`, using a negative lookahead: `.rename(/^x-(?!__proto__$)(.+)$/, Joi.x('{#1}'), { multiple: true })` 3. Drop { multiple: true } from
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-gg4h-3hg2-grpc ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.