CVE-2025-61912
Description
A vulnerability exists in the python-ldap's ldap.dn.escape_dn_chars() helper function, where the null byte (\x00) is improperly escaped by emitting a backslash followed by a literal NUL instead of the required RFC 4514 hex form \00. When this helper is used on untrusted input to build LDAP distinguished names (DNs), it may cause a client-side failure, before any communication with the LDAP server occurs. This results in a client side denial of service (DoS) for parts of the application that rely on the helper for DN construction.
Statement
Availability impact is considered Low, as the flaw is limited to denial of service (client-side) only.
It is important to note that the python-ldap3 package (https://github.com/cannatag/ldap3) is entirely separate and not affected. Only the python-ldap package (https://github.com/python-ldap/python-ldap) contains the vulnerable implementation.
Mitigation
No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability beyond these steps.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | 5.3 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Low | Low | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability
Technical Impact: Read Memory; Execute Unauthorized Code or Commands
The case of an omitted null character is the most dangerous of the possible issues. This will almost certainly result in information disclosure, and possibly a buffer overflow condition, which may be exploited to execute arbitrary code.
Confidentiality,Integrity,Availability
Technical Impact: DoS: Crash, Exit, or Restart; Read Memory; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
If a null character is omitted from a string, then most string-copying functions will read data until they locate a null character, even outside of the intended boundaries of the string. This could: cause a crash due to a segmentation fault cause sensitive adjacent memory to be copied and sent to an outsider trigger a buffer overflow when the copy is being written to a fixed-size buffer.
Integrity,Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart
Misplaced null characters may result in any number of security problems. The biggest issue is a subset of buffer overflow, and write-what-where conditions, where data corruption occurs from the writing of a null character over valid data, or even instructions. A randomly placed null character may put the system into an undefined state, and therefore make it prone to crashing. A misplaced null character may corrupt other data in memory.
Integrity,Confidentiality,Availability,Access Control,Other
Technical Impact: Alter Execution Logic; Execute Unauthorized Code or Commands
Should the null character corrupt the process flow, or affect a flag controlling access, it may lead to logical errors which allow for the execution of arbitrary code.
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