Binutils: Out-of-bounds Write
CVE-2025-0840 is a high-severity out-of-bounds write vulnerability in Binutils from GNU, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected Binutils versions: 2.0; 2.1; 2.2, 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 0.76% chance of exploitation within 30 days, higher than 56% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Binutils you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| GNU | Binutils | 2.0; 2.1; 2.2; 2.3; 2.4; 2.5; 2.6; 2.7; and 32 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
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- 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:H/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.3 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 5.0 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 2.0 | 5.1 | Medium | CNA (vuldb.com) |
Official description
A vulnerability, which was classified as problematic, was found in GNU Binutils up to 2.43. This affects the function disassemble_bytes of the file binutils/objdump.c. The manipulation of the argument buf leads to stack-based buffer overflow. It is possible to initiate the attack remotely. The complexity of an attack is rather high. The exploitability is told to be difficult. The exploit has been disclosed to the public and may be used. Upgrading to version 2.44 is able to address this issue. The identifier of the patch is baac6c221e9d69335bf41366a1c7d87d8ab2f893. It is recommended to upgrade the affected component.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Third-party and government advisories
- vuldb.com/?id.293997Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
- sourceware.org/bugzilla/show_bug.cgi?id=32560Exploit, Issue Tracking
- vuldb.com/?submit.485255Exploit, Third Party Advisory, VDB Entry
Other references
- vuldb.com/?ctiid.293997Permissions Required, VDB Entry
- gnu.org/Product
Other vulnerabilities in Binutils
- 7.8 High severity
- 7.1 High severity
- 7.1 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Out-of-bounds Write vulnerabilities
- 7.5 High severity
- 7.1 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.1 Critical severity
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