Linux: Out-of-bounds Read
CVE-2025-37749 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 529401c8f12ecc35f9ea5d946d5a5596cf172b48, de5a4f0cba58625e88b7bebd88f780c8c0150997, 99aa698dec342a07125d733e39aab4394b3b7e05 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.4% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 529401c8f12ecc35f9ea5d946d5a5596cf172b48 or de5a4f0cba58625e88b7bebd88f780c8c0150997 or 99aa698dec342a07125d733e39aab4394b3b7e05 or b78f2b458f56a5a4d976c8e01c43dbf58d3ea2ca, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.4.293 or 5.10.237 or 5.15.181 or 6.1.135, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 529401c8f12ecc35f9ea5d946d5a5596cf172b48; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, de5a4f0cba58625e88b7bebd88f780c8c0150997; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 99aa698dec342a07125d733e39aab4394b3b7e05; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, b78f2b458f56a5a4d976c8e01c43dbf58d3ea2ca; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, fbaffe8bccf148ece8ad67eb5d7aa852cabf59c8; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, b4c836d33ca888695b2f2665f948bc1b34fbd533; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 1f6eb9fa87a781d5370c0de7794ae242f1a95ee5; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 6e8a6bf43cea4347121ab21bb1ed8d7bef7e732e; and 2 more ranges | 529401c8f12ecc35f9ea5d946d5a5596cf172b48, de5a4f0cba58625e88b7bebd88f780c8c0150997, 99aa698dec342a07125d733e39aab4394b3b7e05, b78f2b458f56a5a4d976c8e01c43dbf58d3ea2ca, fbaffe8bccf148ece8ad67eb5d7aa852cabf59c8, b4c836d33ca888695b2f2665f948bc1b34fbd533 |
| Linux | Linux Kernel | 2.6.13 up to, but not including, 5.4.293; 5.5 up to, but not including, 5.10.237; 5.11 up to, but not including, 5.15.181; 5.16 up to, but not including, 6.1.135; 6.2 up to, but not including, 6.6.88; 6.7 up to, but not including, 6.12.24; 6.13 up to, but not including, 6.13.12; 6.14 up to, but not including, 6.14.3; and 2 more ranges | 5.4.293, 5.10.237, 5.15.181, 6.1.135, 6.6.88, 6.12.24 |
| Debian | Debian Linux | 11.0 | 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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.2 | High | CNA |
| CVSS 3.1 | 7.1 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: net: ppp: Add bound checking for skb data on ppp_sync_txmung Ensure we have enough data in linear buffer from skb before accessing initial bytes. This prevents potential out-of-bounds accesses when processing short packets. When ppp_sync_txmung receives an incoming package with an empty payload: (remote) gef➤ p *(struct pppoe_hdr *) (skb->head + skb->network_header) $18 = { type = 0x1, ver = 0x1, code = 0x0, sid = 0x2, length = 0x0, tag = 0xffff8880371cdb96 } from the skb struct (trimmed) tail = 0x16, end = 0x140, head = 0xffff88803346f400 "4", data = 0xffff88803346f416 ":\377", truesize = 0x380, len = 0x0, data_len = 0x0, mac_len = 0xe, hdr_len = 0x0, it is not safe to access data[2]. [[email protected]: fixed subj typo]
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/1f6eb9fa87a781d5370c0de7794ae242f1a95ee5
- git.kernel.org/stable/c/529401c8f12ecc35f9ea5d946d5a5596cf172b48
- git.kernel.org/stable/c/6e8a6bf43cea4347121ab21bb1ed8d7bef7e732e
- git.kernel.org/stable/c/99aa698dec342a07125d733e39aab4394b3b7e05
- git.kernel.org/stable/c/aabc6596ffb377c4c9c8f335124b92ea282c9821
- git.kernel.org/stable/c/b4c836d33ca888695b2f2665f948bc1b34fbd533
- git.kernel.org/stable/c/b78f2b458f56a5a4d976c8e01c43dbf58d3ea2ca
- git.kernel.org/stable/c/de5a4f0cba58625e88b7bebd88f780c8c0150997
- git.kernel.org/stable/c/fbaffe8bccf148ece8ad67eb5d7aa852cabf59c8
Other references
Recent Out-of-bounds Read vulnerabilities
- 8.8 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
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