git: Integer Overflow or Wraparound
CVE-2022-41903 is a critical-severity integer overflow or wraparound vulnerability in git, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected git versions: < 2.30.7; >= 2.31.0, < 2.31.6; >= 2.32.0, < 2.32.5, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 44.3% chance of exploitation within 30 days, which is in the top 1.22% of all scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of git you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on git-scm.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Git | git | < 2.30.7; >= 2.31.0, < 2.31.6; >= 2.32.0, < 2.32.5; >= 2.33.0, < 2.33.6; >= 2.34.0, < 2.34.6; >= 2.35.0, < 2.35.6; >= 2.36.0, < 2.36.4; >= 2.37.0, < 2.37.5; and 2 more ranges | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Git is distributed revision control system. `git log` can display commits in an arbitrary format using its `--format` specifiers. This functionality is also exposed to `git archive` via the `export-subst` gitattribute. When processing the padding operators, there is a integer overflow in `pretty.c::format_and_pad_commit()` where a `size_t` is stored improperly as an `int`, and then added as an offset to a `memcpy()`. This overflow can be triggered directly by a user running a command which invokes the commit formatting machinery (e.g., `git log --format=...`). It may also be triggered indirectly through git archive via the export-subst mechanism, which expands format specifiers inside of files within the repository during a git archive. This integer overflow can result in arbitrary heap writes, which may result in arbitrary code execution. The problem has been patched in the versions published on 2023-01-17, going back to v2.30.7. Users are advised to upgrade. Users who are unable to upgrade should disable `git archive` in untrusted repositories. If you expose git archive via `git daemon`, disable it by running `git config --global daemon.uploadArch false`.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Integer Overflow or Wraparound
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
How developers prevent this class of flaw
- Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Use libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).
More Integer Overflow or Wraparound vulnerabilities (CWE-190)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
- github.com/git/git/commit/508386c6c5857b4faa2c3e491f422c98cc69ae76Release Notes, Third Party Advisory
Other references
Other vulnerabilities in git
- 7.5 High severity
- 8.6 High severity
- 8.0 High severity
Git Link Following Exploited
- 8.8 High severity
- 7.5 High severity
- 7.8 High severity
Recent Integer Overflow or Wraparound vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 7.1 High severity
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