Apache Log4j 1.x: Improper Neutralization of Special Elements used in an SQL Command
CVE-2022-23305 is a critical-severity improper neutralization of special elements used in an SQL command vulnerability in Apache Log4j 1.x from Apache, 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. The record lists version 2.0-alpha1 as the first without the flaw, so updating Apache Log4j 1.x to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 66.5% chance of exploitation within 30 days, which is in the top 0.7% of all scored CVEs.
Exploitation in the next 30 days is more likely than not, according to EPSS.
What to do
- Update Apache Log4j 1.x to 2.0-alpha1 or a later version.
- Update Reload4j to 1.2.18.2 or a later version.
- Update Communications Offline Mediation Controller to 12.0.0.4.4 or a later version.
- Read the advisory on lists.apache.org 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
Version data comes from the organisation that assigned the CVE; 4 further products are omitted here. 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 | NVD |
| CVSS 3.1 | 9.8 | Critical | CISA (ADP) |
| CVSS 2.0 | 6.8 | Medium | NVD |
Official description
By design, the JDBCAppender in Log4j 1.2.x accepts an SQL statement as a configuration parameter where the values to be inserted are converters from PatternLayout. The message converter, %m, is likely to always be included. This allows attackers to manipulate the SQL by entering crafted strings into input fields or headers of an application that are logged allowing unintended SQL queries to be executed. Note this issue only affects Log4j 1.x when specifically configured to use the JDBCAppender, which is not the default. Beginning in version 2.0-beta8, the JDBCAppender was re-introduced with proper support for parameterized SQL queries and further customization over the columns written to in logs. Apache Log4j 1.2 reached end of life in August 2015. Users should upgrade to Log4j 2 as it addresses numerous other issues from the previous versions.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in an SQL Command
The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.
How developers prevent this class of flaw
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using persistence layers such as Hibernate or Enterprise Java Beans, which can provide significant protection against SQL injection if used properly.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
More Improper Neutralization of Special Elements used in an SQL Command vulnerabilities (CWE-89)
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
- lists.apache.org/thread/pt6lh3pbsvxqlwlp4c5l798dv2hkc85yIssue Tracking, Mailing List
- logging.apache.org/log4j/1.2/index.html
Patches and release notes
- oracle.com/security-alerts/cpuapr2022.htmlThird Party Advisory
- oracle.com/security-alerts/cpujul2022.htmlThird Party Advisory
Third-party and government advisories
- openwall.com/lists/oss-security/2022/01/18/4Mailing List, Third Party Advisory
- security.netapp.com/advisory/ntap-20220217-0007/Third Party Advisory
Other vulnerabilities in Apache Log4j 1.x
- 8.8 High severity
- 8.8 High severity
Recent Improper Neutralization of Special Elements used in an SQL Command vulnerabilities
- 9.8 Critical severity
- 7.2 High severity
- 8.8 High severity
- 7.5 High severity
- 7.2 High severity
- 9.8 Critical severity
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