GHSA-jjjr-3jcw-f8v6 CVE-2020-11037 PYSEC-2020-153
Potential Observable Timing Discrepancy in Wagtail
- Severity
- 0.0 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- 0.25%
- Chance of exploitation in the next 30 days. Higher than 16.38% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-208 Observable Timing Discrepancy
- CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
- Fix
2.7.3- Upgrade wagtail to this version or later
Description
Impact
A potential timing attack exists on pages or documents that have been protected with a shared password through Wagtail's "Privacy" controls. This password check is performed through a character-by-character string comparison, and so an attacker who is able to measure the time taken by this check to a high degree of accuracy could potentially use timing differences to gain knowledge of the password. (This is understood to be feasible on a local network, but not on the public internet.)
Privacy settings that restrict access to pages / documents on a per-user or per-group basis (as opposed to a shared password) are unaffected by this vulnerability.
Patches
Patched versions have been released as Wagtail 2.7.3 (for the LTS 2.7 branch), Wagtail 2.8.2 and Wagtail 2.9.
Workarounds
Site owners who are unable to upgrade to the new versions can use user- or group-based privacy restrictions to restrict access to sensitive information; these are unaffected by this vulnerability.
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| wagtail | < 2.7.3 |
2.7.3 |
| wagtail | >= 2.8rc1, < 2.8.2 |
2.8.2 |
| wagtail | >= 2.9rc1, < 2.9 |
2.9 |
| wagtail | >= 2.7, < 2.7.3>= 2.8, < 2.8.2 |
2.7.32.8.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
wagtail PyPI → 2.7.3
- pip
pip install --upgrade "wagtail>=2.7.3"- poetry
poetry add "wagtail>=2.7.3"- uv
uv add "wagtail>=2.7.3"
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N
- Attack vector
- Local
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- High
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- High
- Integrity (subsequent systems)
- Low
- Availability (subsequent systems)
- None
CVSS 3.1 6.1
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:N
- Attack vector
- Local
- Attack complexity
- High
- Privileges required
- High
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Weakness
CWE-208: Observable Timing Discrepancy
Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.
CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
How to prevent it
- Architecture and Design: In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
- Architecture and Design: Use thread-safe capabilities such as the data access abstraction in Spring.
- Architecture and Design: Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).
- Implementation: When using multithreading and operating on shared variables, only use thread-safe functions.
- Implementation: Use atomic operations on shared variables. Be wary of innocent-looking constructs such as "x++". This may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read, followed by a computation, followed by a write.
- Implementation: Use a mutex if available, but be sure to avoid related weaknesses such as CWE-412.
- Implementation: Avoid double-checked locking (CWE-609) and other implementation errors that arise when trying to avoid the overhead of synchronization.
- Implementation: Disable interrupts or signals over critical parts of the code, but also make sure that the code does not go into a large or infinite loop.
- Implementation: Use the volatile type modifier for critical variables to avoid unexpected compiler optimization or reordering. This does not necessarily solve the synchronization problem, but it can help.
- Architecture and Design, Operation: Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
References
Advisories
Packages
Other links
- github.com/wagtail/wagtail/security/advisories/GHSA-jjjr-3jcw-f8v6
- github.com/wagtail/wagtail/commit/3c030490ed575bb9cd01dfb3a890477dcaeb2edf
- github.com/wagtail/wagtail/commit/b76ab57ee859732b9cf9287d380493ab24061090
- github.com/wagtail/wagtail/commit/ba9d424bd1ca5ce1910d3de74f5cc07214fbfb11
- github.com/wagtail/wagtail/commit/bac3cd0a26b023e595cf2959aae7da15bb5e4340
- github.com/pypa/advisory-database/tree/main/vulns/wagtail/PYSEC-2020-153.yaml
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-jm5p-837g-rv8g Wagtail: Improper restriction handling on Page translation API endpoint | Medium | Also affects wagtail |
| GHSA-x5cx-w6p2-mxf2 Wagtail: Improper permission handling when copying snippets | Medium | Also affects wagtail |
| GHSA-c2xx-cjmh-9q8f Wagtail: Improper restriction handling on descendant collections in Documents and Images API | Medium | Also affects wagtail |
| GHSA-92hv-j533-69wc Wagtail: Identification of documents by SHA1 hash | Low | Also affects wagtail |
| GHSA-3vrh-m9w7-v94f Wagtail: Improper restriction handling on Pages admin API | Medium | Also affects wagtail |
| GHSA-23m2-mghx-vqmf Wagtail: Reflected XSS in dynamic image URL generator view | High | Also affects wagtail |
| GHSA-8634-mr4j-r72c Wagtail: Pages translations can be created without page permissions when using simple_translation | Medium | Also affects wagtail |
| GHSA-r6p4-grq7-xm4m Wagtail: Improper permission handling in image preview | Medium | Also affects wagtail |
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