[SERVER-44154] Consider making FCV checks for $-prefixed field names Created: 22/Oct/19 Updated: 06/Dec/22 Resolved: 05/Nov/19 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Querying |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Task | Priority: | Major - P3 |
| Reporter: | Ian Boros | Assignee: | Backlog - Query Team (Inactive) |
| Resolution: | Won't Fix | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Assigned Teams: |
Query
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| Participants: |
| Description |
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In 4.2, $-prefixed field names were banned everywhere in agg. In 4.4, there is a small whitelist of field names permitted to start with $.
If a user were to create a view, or a validator (and use $expr) with a $-prefixed field name in FCV 4.2, they may not be able to downgrade without dropping views/collections with a 4.4. binary. |
| Comments |
| Comment by Ian Boros [ 31/Oct/19 ] |
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I'm tempted to close this as "won't fix." This would be a relatively large amount of work for what I suspect is an unlikely case that only an "adversarial" user would find. Even if such a case happened, they could downgrade by using a 4.4 binary to drop the relevant view/collection. I'm not sure what our policy is on this kind of thing, however, so I'm flagging this for triage. |