CVE-2024-7264
Description
A flaw was found in libcurl, where libcurl's ASN1 parser code has the GTime2str() function, used for parsing an ASN.1 Generalized Time field. If a syntactically incorrect field is given, the parser can use -1 for the length of the time fraction, leading to a strlen() performed on a pointer to a heap buffer area that is not purposely NULL terminated.
Statement
The vulnerability is classified as low severity because it primarily results in a heap buffer over-read rather than a direct memory corruption or code execution risk. Since the ASN.1 parsing occurs after a successful TLS handshake, the malformed certificate must first bypass the TLS library's validation, which significantly reduces the likelihood of exploitation.
Additionally, the impact is limited to a potential crash or unintended heap data exposure through CURLINFO_CERTINFO, but not arbitrary code execution. The requirement for a specific TLS backend configuration and the controlled nature of the memory read further minimize its exploitability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Red Hat build of curl uses OpenSSL, which is not included in the affected list of GnuTLS, Schannel, Secure Transport and mbedTLS. Inspect which TLS backend is in use by running:
$ curl --version
Check the reference for curl handled by the maintainers which may contain more relevant information around this vulnerability.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | 6.5 | 6.3 |
| Attack Vector | Local | Network | Network |
| Attack Complexity | High | Low | Low |
| Privileges Required | Low | None | Low |
| User Interaction | None | Required | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | None | Low |
| Integrity Impact | None | None | Low |
| Availability Impact | High | High | Low |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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