docs: Fix typo under build/building-apps/04-security-part-1.md (cosmo…

…s#20276)

docs/build/building-apps/04-security-part-1.md

@@ -203,7 +203,7 @@ Due to [challenges with how Cosmos SDK gas estimation works](https://github.com/
 
 If the chain increases gas usage in ways that are not included in simulation logic, this could break many clients at chain upgrade time until they increase their gas multipliers.
 
-The specific area to pay attention to on this front is the `simulate` parameter in the `AnteHander` API. An example that could cause issues might look like the following:
+The specific area to pay attention to on this front is the `simulate` parameter in the `AnteHandler` API. An example that could cause issues might look like the following:
 
 ```go
 func (mfd MyMemPoolDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
@@ -252,8 +252,8 @@ The following are NOT in the state-machine scope:
 * Errors (assuming use of Go-native errors)
 * ABCI 2.0 `PrepareProposal`
 * ABCI 2.0 `ExtendVote`
-* `AnteHander`s in any mode other than `execModeFinalize`
-* `PostHander`s in any mode other than `execModeFinalize`
+* `AnteHandler`s in any mode other than `execModeFinalize`
+* `PostHandler`s in any mode other than `execModeFinalize`
 
 ### Key Malleability and Prefix Iteration Attack Example