### Summary `TemplateLookup.get_template()` is vulnerable to path traversal when a URI starts with `//` (e.g., `//../../../secret.txt`). The root cause is an inconsistency between two slash-stripping implementations: - `Template.__init__` strips **one** leading `/` using `if`/slice - `TemplateLookup.get_template()` strips **all** leading `/` using `re.sub(r"^\/+", "")` When a URI like `//../../../../etc/passwd` is passed: 1. `get_template()` strips all `/` → `../../../../etc/passwd` → file found via `posixpath.join(dir_, u)` 2. `Template.__init__` strips one `/` → `/../../../../etc/passwd` → `normpath` → `/etc/passwd` 3. `/etc/passwd`.startswith(`..`) → `False` → **check bypassed** ### Impact Arbitrary file read: any file readable by the process can be returned as rendered template content when an application passes untrusted input directly to `TemplateLookup.get_template()`. Note: this is exploitable at the library API level. HTTP-based exploitation is mitigated by Python's `BaseHTTPRequestHandler` which normalizes double-slash prefixes since CPython gh-87389. Applications using other HTTP servers that do not normalize paths may be affected. ### Fix Changed `Template.__init__` to use `lstrip("/")` instead of stripping only a single leading slash, so both code paths handle leading slashes consistently.
### Summary `TemplateLookup.get_template()` is vulnerable to path traversal when a URI starts with `//` (e.g., `//../../../secret.txt`). The root cause is an inconsistency between two slash-stripping implementations: - `Template.__init__` strips **one** leading `/` using `if`/slice - `TemplateLookup.get_template()` strips **all** leading `/` using `re.sub(r"^\/+", "")` When a URI like `//../../../../etc/passwd` is passed: 1. `get_template()` strips all `/` → `../../../../etc/passwd` → file found via `posixpath.join(dir_, u)` 2. `Template.__init__` strips one `/` → `/../../../../etc/passwd` → `normpath` → `/etc/passwd` 3. `/etc/passwd`.startswith(`..`) → `False` → **check bypassed** ### Impact Arbitrary file read: any file readable by the process can be returned as rendered template content when an application passes untrusted input directly to `TemplateLookup.get_template()`. Note: this is exploitable at the library API level. HTTP-based exploitation is mitigated by Python's `BaseHTTPRequestHandler` which normalizes double-slash prefixes since CPython gh-87389. Applications using other HTTP servers that do not normalize paths may be affected. ### Fix Changed `Template.__init__` to use `lstrip("/")` instead of stripping only a single leading slash, so both code paths handle leading slashes consistently.
Update Mako to 1.3.11 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanMako: Path traversal via double-slash URI prefix in TemplateLookup affects Mako (pip). Severity is high. ### Summary `TemplateLookup.get_template()` is vulnerable to path traversal when a URI starts with `//` (e.g., `//../../../secret.txt`). The root cause is an inconsistency between two slash-stripping implementations: - `Template.__init__` strips **one** leading `/` using `if`/slice - `TemplateLookup.get_template()` strips **all** leading `/` using `re.sub(r"^\/+", "")` When a URI like `//../../../../etc/passwd` is passed: 1. `get_template()` strips all `/` → `../../../../etc/passwd` → file found via `posixpath.join(dir_, u)` 2. `Template.__init__` strips one `/` → `/../../../../etc/passwd` → `normpath` → `/etc/passwd` 3. `/etc/passwd`.startswith(`..`) → `False` → **check bypassed** ### Impact Arbitrary file read: any file readable by the process can be returned as rendered template content when an application passes untrusted input directly to `TemplateLookup.get_template()`. Note: this is exploitable at the library API level. HTTP-based exploitation is mitigated by Python's `BaseHTTPRequestHandler` which normalizes double-slash prefixes since CPython gh-87389. Applications using other HTTP servers that do not normalize paths may be affected. ### Fix Changed `Template.__init__` to use `lstrip("/")` instead of stripping only a single leading slash, so both code paths handle leading slashes consistently.
AI coding agents often install or upgrade packages automatically in pip. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| Makopip | <=1.3.10 | 1.3.11 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate Mako to 1.3.11 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanMako: Path traversal via double-slash URI prefix in TemplateLookup affects Mako (pip). Severity is high. ### Summary `TemplateLookup.get_template()` is vulnerable to path traversal when a URI starts with `//` (e.g., `//../../../secret.txt`). The root cause is an inconsistency between two slash-stripping implementations: - `Template.__init__` strips **one** leading `/` using `if`/slice - `TemplateLookup.get_template()` strips **all** leading `/` using `re.sub(r"^\/+", "")` When a URI like `//../../../../etc/passwd` is passed: 1. `get_template()` strips all `/` → `../../../../etc/passwd` → file found via `posixpath.join(dir_, u)` 2. `Template.__init__` strips one `/` → `/../../../../etc/passwd` → `normpath` → `/etc/passwd` 3. `/etc/passwd`.startswith(`..`) → `False` → **check bypassed** ### Impact Arbitrary file read: any file readable by the process can be returned as rendered template content when an application passes untrusted input directly to `TemplateLookup.get_template()`. Note: this is exploitable at the library API level. HTTP-based exploitation is mitigated by Python's `BaseHTTPRequestHandler` which normalizes double-slash prefixes since CPython gh-87389. Applications using other HTTP servers that do not normalize paths may be affected. ### Fix Changed `Template.__init__` to use `lstrip("/")` instead of stripping only a single leading slash, so both code paths handle leading slashes consistently.
AI coding agents often install or upgrade packages automatically in pip. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| Makopip | <=1.3.10 | 1.3.11 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard