iOS Backup Version Patcher

A small Python utility to edit the Product/Build versions inside iPhone/iPad backup bundles so you can attempt to restore backups when downgrading iOS/iPadOS.

Important: This is not guaranteed to make a backup restorable on a downgraded system. Restores may still fail depending on the backup contents and OS constraints. Proceed at your own risk.

What it does

• Reads current versions and shows them for confirmation.
• Updates two files in the backup bundle root:
  • Info.plist: sets top‑level Product Version and Build Version.
  • Manifest.plist: sets Lockdown/ProductVersion and Lockdown/BuildVersion (keys without spaces under the Lockdown dictionary).
• Preserves the original plist format (binary or XML) and writes atomically.
• Optional .bak file creation with --backup.

Requirements

• Python 3.8+
• macOS optional tools for verification:
  • plutil (ships with macOS)
  • PlistBuddy (ships with Xcode tools)

Usage

Interactive (recommended first run):

python update_backup_version.py \
  "/path/to/Your Device-YYYYMMDD-HHMM.mobiletransfer"

• The script will display current versions, ask “Overwrite with new version? (Y/N)”, and then prompt for new values if you confirm.

Provide versions via flags (still asks to confirm):

python update_backup_version.py \
  "/path/to/Your Device-YYYYMMDD-HHMM.mobiletransfer" \
  --version 17.0 --build 21A123

Create .bak backups before writing:

python update_backup_version.py \
  "/path/to/Your Device-YYYYMMDD-HHMM.mobiletransfer" \
  --version 17.0 --build 21A123 --backup

Verifying changes

Binary plists won’t display correctly with cat. Use one of the following:

• plutil (macOS):

plutil -p \
  "/path/to/.../Manifest.plist" | sed -n '1,120p'

plutil -p \
  "/path/to/.../Info.plist" | sed -n '1,120p'

• PlistBuddy (macOS):

/usr/libexec/PlistBuddy -c "Print :Lockdown" \
  "/path/to/.../Manifest.plist"

Notes and limitations

• Not a guaranteed fix: Some backups cannot be restored after downgrading due to system and app data compatibility.
• Scope is limited: Only the version keys listed above are modified; other compatibility markers (if any) are untouched.
• Atomic writes: Files are replaced atomically to reduce corruption risk. Use --backup if you want .bak copies.
• Permissions: The tool attempts to preserve original file permissions when overwriting.

Example

Sample output flow:

Current values:
- Info.plist: Product Version='18.6.2', Build Version='22G100'
- Manifest.plist/Lockdown: ProductVersion='18.6.2', BuildVersion='22G100'
Overwrite with new version? (Y/N): Y
Enter Product Version (e.g., 17.0): 17.0
Enter Build Version (e.g., 21A123): 21A123
Updated Info.plist: Product Version -> 17.0, Build Version -> 21A123
Updated Manifest.plist: Product Version -> 17.0, Build Version -> 21A123
Done: Plists updated as requested.

License

No license specified. Use at your own risk.