🛡️ Sentinel: [MEDIUM] Fix readline input integer overflow vulnerability

.jules/sentinel.md

@@ -2,3 +2,8 @@
 **Vulnerability:** Unvalidated inputs passed to `if()` statements can cause process crashes (`condition has length > 1`) or unexpected coercion vulnerabilities.
 **Learning:** In R, optional boolean parameters that default to `NULL` should be validated using explicit runtime type validation (e.g., `if (!is.null(flag) && (!is.logical(flag) || length(flag) != 1 || is.na(flag)))`).
 **Prevention:** Always implement explicit runtime type validation for optional boolean parameters.
+
+## 2024-07-18 - Fix Integer Overflow Coercion in readline Input Validation
+**Vulnerability:** In `R/aFIPC.R`, the application used a permissive regex `^[0-9]+$` to validate numeric interactive inputs from `readline()` before coercing them with `as.integer()`. An attacker could input an excessively long numeric string (e.g., `999999999999999999999`), which bypasses the regex check but evaluates to `NA` during coercion, leading to an unexpected state or subsequent process crashes due to integer overflow.
+**Learning:** R's `as.integer()` fails silently with a warning and returns `NA` when given numbers exceeding the 32-bit integer limits, making broad regex checks like `^[0-9]+$` insufficient for safe parsing of integer inputs intended for program control flow.
+**Prevention:** Always match against the specific, finite set of expected valid inputs (e.g., `^[12]$`) when validating numerical inputs from `readline()` before parsing, preventing integer overflow and logic bypass vulnerabilities.

DESCRIPTION

@@ -10,7 +10,7 @@ Description: Automates fixed item parameter linking for test linking under
     the item response theory paradigm using mirt package estimates.
 License: GPL-3 | file LICENSE
 Imports: mirt, methods
-Suggests: testthat (>= 3.0.0)
+Suggests: testthat (>= 3.0.0), mockery
 Encoding: UTF-8
 Config/testthat/edition: 3
 Config/roxygen2/version: 8.0.0

R/aFIPC.R

@@ -141,7 +141,7 @@ autoFIPC <-
       }
       for (attempt in seq_len(3)) {
         n <- readline(prompt = "Is it correct? (1: Yes 2: No) : ")
-        if (grepl("^[0-9]+$", n)) {
+        if (grepl("^[12]$", n)) {
           return(as.integer(n))
         }
       }
@@ -171,7 +171,7 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for oldform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }
@@ -390,7 +390,7 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for newform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }

tests/testthat/test-sentinel-validation.R

@@ -35,3 +35,44 @@ test_that("autoFIPC validates boolean flags for newformBILOGprior, oldformBILOGp
     "Security Error: confirmCommonItems must be a single non-NA logical value or NULL"
   )
 })
+
+test_that("autoFIPC integer overflow in interactive prompt validation", {
+  # Mock interactive environment and multiple invalid readline inputs
+  mock_interactive <- mockery::mock(TRUE, cycle = TRUE)
+  mockery::stub(aFIPC::autoFIPC, "interactive", mock_interactive)
+
+  # Check validation for checkCorrect() common items prompt
+  mock_readline_common <- mockery::mock("999999999999999999", "abc", "0", cycle = TRUE)
+  mockery::stub(aFIPC::autoFIPC, "readline", mock_readline_common)
+
+  expect_error(
+    aFIPC::autoFIPC(
+      newformXData = data.frame(A=1),
+      oldformYData = data.frame(A=2),
+      newformCommonItemNames = c('A'),
+      oldformCommonItemNames = c('A'),
+      confirmCommonItems = NULL
+    ),
+    "Too many invalid common item confirmation attempts"
+  )
+
+  # Validate interactive readline validation accepts 1
+  mock_readline_success <- mockery::mock("1", "1", "1", cycle = TRUE)
+
+  mockery::stub(aFIPC::autoFIPC, "interactive", mock_interactive)
+  mockery::stub(aFIPC::autoFIPC, "readline", mock_readline_success)
+
+  # For oldformBILOGprior interactive prompt
+  expect_error(
+    aFIPC::autoFIPC(
+      newformXData = data.frame(A=c(1,0,1,0)),
+      oldformYData = data.frame(A=c(1,1,0,0)),
+      newformCommonItemNames = c('A'),
+      oldformCommonItemNames = c('A'),
+      confirmCommonItems = NULL,
+      itemtype = '3PL',
+      oldformBILOGprior = NULL
+    ),
+    "Security Error: oldformYData must be a data.frame, matrix, or a valid fitted mirt model|Security Error: Initial estimation of oldFormModel completely failed|Common Items are not equal|Security Error: itemtype must be length|The following items have only one response category|Too few degrees of freedom"
+  )
+})